DOCSLIB.ORG

Induction of Cell Growth Regulatory Genes by P53

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Induction of Cell Growth Regulatory Genes by P53 CANCER RESEARCH 56. 5384-5390. December 1. 996] Induction of Cell Growth Regulatory Genes by p53 Stephen L. Madden,1 Elizabeth A. Galella, Deborah Riley, Arthur H. Bertelsen, and Gary A. Beaudry Department of Molecular and Cellular Biology. PharmaGenics. Inc., Allendale. New Jersey 07401 ABSTRACT kinase inhibitor by directly interacting with cyclin-dependent kinase proteins during progression of the cell cycle (20). Overexpressiom of Transcriptionally regulated growth-response genes play a pivotal role @2jWAF@@'I via transfection suppresses cell growth in a wide array in the determination of the fate of a cell.p53 is known to transcriptionally of cancer cell lines. In contrast, MDM2 functions by negatively regulate genes important in regulating cell growth potential. Using differ ential reverse transcription-PCR analysis of rat embryo fibroblast cells regulating p53 activity, and overexpression of MDM2 leads to un containing a temperature-sensitive p53 allele, we were able to isolate controlled cell growth and tumorigenesis (8). However, p53-induced several transcripts up-regulated specifically in cells harboring functional transcriptional responses appear ill-conserved, suggesting that cell PS3 protein. Two of these genes, SM2Oand microsomal epoxide hydrolase type-, genetic-, and species-dependent factors may contribute to p53 (mElt), are previously described genes. Two previously uncharacterized responsiveness; for example, both @2JwAFl/cIPIand MDM2 are tran cDNAs, cell growth regulatory (CGR) genes CGRJJ and CGRJ9, were scriptionally activated in a p53-dependent manner in rodent cells isolated. The predicted amino acid sequence of these novel proteins con harboring a temperature-sensitive p53 allele, but only MDM2 is tamknownmotifs;EF-handdomains(CGR11)anda ring-fingerdomaln induced in an analogous human system (30). In addition, activation of (CGRJ9),suggestiveoffunction. CGRJJand CGRJ9appearto beprimary @2jWAF1@@'I has been shown to be both p53-dependent and -mdc response genes expressed to moderate levels in functional p53 cells. Both pendent, suggesting alternate pathways for regulation of its expression CGRIJ and CGRJ9 are able to inhibit the growth of several cell lines. (31, 32). Furthermore, it appears that the levels of apoptotic regulatory gene products, such as BCL2 or E1B, are influential in determining if INTRODUCTION a cell will undergo p53-dependent growth arrest or apoptosis (9, 33). These results suggest that a complex regulatory cascade, using nu Significant advances have been made recently toward the identifi merous effector gene products, determines cell growth potential. The cation of numerous potential growth effectors within cells. Although complexities of cell growth regulation underscores the need to further previous analyses have evaluated the phenotypic effects of cellular define the relevant molecular determinants. environment, growth factors and stress, it is only recently that the The well-characterized murine temperature-sensitive p53 mutation underlying molecular events responsible for perturbing cell growth (VAL13S) has been used to further characterize potential transcrip are beginning to be defined. In a large number of cases, the cause of tional responses of wild-type p53 protein. Growth of rat embryo a particular cellular growth response can be attributed to transcrip fibroblast cells (REF-l 12) transformed with activated RAS and p.53- tional artenuation (1, 2). Indeed, the recent gene discoveries directly VAL135 is temperature sensitive ( 10, 34). Growth of REF- 112 cells relevant to cell cycle regulation have been based, to a significant at 38°Cmaintains the p53 protein in a nonfunctional conformation degree, on differential gene expression analyses (2—4). complexed with HSP7O in the cytoplasm (10, 35). When the cells are The p53 gene remains the most frequenfly mutated gene in human shifted to 32°C,the p53 protein adopts a functional, wild type-like cancers, undoubtedly reflecting an important regulatory function for conformation, migrates into the nucleus, and regulates the transcrip this gene in controlling cell growth (reviewed in Ref. 5). p53 function tion of target genes (10). Under these latter conditions, the cells were can be attenuated by interaction with viral or cellular proteins (6—9) initially described as being growth-arrested predominately in the G1 and cytoplasmic sequestration (10, 11), ultimately leading to alter phase of the cell cycle (34). However, we have observed that a ations in cell growth potential. Although p53 is thought to exert significant population of cells undergo apoptosis when maintained at growth-regulatory functions in response to DNA damage and by 32°C.DNA laddering indicative of apoptotic cells was observed as directly inhibiting DNA replication ( 12, 13) or inducing apoptosis (9), early as 6 h after shift of cells to the permissive temperature (data not a large body of data indicates that the primary function of p53 is to shown).2 Because previous studies have suggested that p53-induced transcriptionally regulate downstream effector genes. p53 contains a growth arrest and apoptosis might be in distinct and divergent path potent transcriptional activation domain and is able to bind DNA in a ways (12, 31, 36, 37), both apoptotic-specific as well as growth sequence-specific manner (14—16), allowing for both transcriptional arrest-specific genes might be elevated in this system upon shift of activation and repression of target genes (17, 18). p53-mediated p53 to a functional conformation. Utilizing differential display anal transcriptional repression has also been proposed to occur via p53 ysis of temperature-sensitive, p53-induced (32°C), and uninduced protein interaction with general transcription factors (19). (38°C)REF-l 12 cells, we have been able to demonstrate several Identification of the p53 transcriptionally responsive genes genes the transcript levels of which are significantly elevated in the p2IW@)l (2, 20), MDM2 (1, 8), GADD45 (21, 22), H/C (23), presence of functional p53. Two of these genes are previously unde cyclin G (24, 25), and BAX (26—29),the products of which have been scribed and encode proteins containing known functional motifs. We suggested to have direct effects on cell growth, emphasizes the pivotal demonstrate here that these genes have growth-suppressive potential role of pS3 in modulating expression levels of growth-response genes. in several cell lines examined. To date, two of the best characterized direct effectors of cell growth that are transcriptionally regulated by p53 include @2jWAFI/CIPI(2, MATERIALS AND METHODS 20) and MDM2 (I, 8). @2jWAFI/CIPlfunctions as a cyclin-dependent Cell Culture. Rat embryo fibroblast cells REF-I 12 (p53-VAL135) and Received 5/3 1/96; accepted 10/2/96. REF-132 [p53-PHE132; kindly provided by B. Vogelstein (Johns Hopkins The costs of publication of this article were defrayed in part by the payment of page University, Baltimore, MD) and M. Orem (Weizmanm Institute, Rehovot, charges. This article must therefore be hereby marked advertisement in accordance with Israel)1,were grown in DMEM containing 10%fetal bovine serum in 5% CO2 18 U.S.C. Section 1734 solely to indicate this fact. @ To whom requests for reprints should be addressed, at Department of Molecular and @ Cellular Biology, PharmaGenics, Inc., 4 Pearl Court, Allendale, NJ 07401. 2 Thou, personal communication. 5384 Downloaded from cancerres.aacrjournals.org on September 30, 2021. © 1996 American Association for Cancer Research. CELL GROWTH REGULATORY GENES a b c 0 1 2 4 6 810 32 38 3238 @NlIWAF1 — iii cycin Fig. I. Characterization of REF-112 RNA. a, kinetics of @2JwAFI/cIP1induction. Total RNA from REF-l 12 cells maintained at 32°Cfor the indicated times (h) was probed with ratp21WAFI@Cll'IcDNA. b, cyclin G RT-PCR. Total RNA harvested from REF-l 12 cells maintained at 38°C,or 32°Cfor 8 h, was reverse-transcribed with an anchored olido(dT) primer. PCR was performed with this primer and a primer specific for the 3' end of rat cyclin G. The arrowhead shows an —300-bp,differentiallyexpressed rat cyclimG RT-PCR product. c, Northern analysis of total RNA from REF-112 cells. The cyclin G RT-PCR cDNA described in b was used as a probe for RNA isolated from 38°C-or 32°C-maintained REF-i 12 cells. at either 38°Cor32°C.Cellswere split and seeded 48 h before any temperature performed in a thermocycler for 40 cycles of: 94°Cfor 3 s, 40°Cfor 2 mm, and shifts. Temperature shifts were performed by simple transfer of subconfluent 72°Cfor 30 s. Reactions were terminated by the addition of 38% formamide, flasks to preequilibrated incubators without media changes. For transfections, 8 mr@iEDTA, 0.02% bromphenol blue, and xylene cylanol. Samples were 4 X iO@cells(T98G and SW480 cells) or 0.8 X l0@cells (SKOV3-IP1) were heated for 2 mm at 70°Cand run on a 6% denaturing polyacrylamide gel. PCR seeded in six-well dishes. Transfections were performed using lipofectin (Life products were purified after drying the gel onto Whatmann 3MM paper and Technologies, Inc.) as described by the manufacturer. Briefly, 40 @.dofreduced exposure to film. Excised bands were resuspended in 120p.1of H20 for 10mm serum medium (Optimem; Life Technologies, Inc.) was added to 2 @.tgofDNA at room temperature, followed by 15 mm of boiling. Debris was pelleted by (pCEP4 derivatives; InVitrogen). A 50-pd mixture containing 10 @doflipo centrifugation, and 10 p.1 of 3 M sodium acetate, 5 p.1 of 10 mg/mI glycogen, fectin and 40 ,.d of Optimem was added to the DNA mixture. After a 15-ruin and 400 p.1of ethanol were added to 100 p.1of the eluted DNA. DNA was room temperature incubation, 1 ml of Optimem was added, and the mixture allowed to precipitate overnight at —20°C.TheDNA was pelleted, amplified was overlayed onto Optimem-washed cells. Cells were allowed to incubate for using the same primers used for the original RT-PCR, gel purified, and cloned 5 h in a 37°C/5% CO2 incubator, following which the transfection mixture was into pCRH (InVitrogen).
Load more

Recommended publications
  • Introduction to the Cell Cell History Cell Structures and Functions
    Introduction to the cell cell history cell structures and functions CK-12 Foundation December 16, 2009 CK-12 Foundation is a non-profit organization with a mission to reduce the cost of textbook materials for the K-12 market both in the U.S. and worldwide. Using an open-content, web-based collaborative model termed the “FlexBook,” CK-12 intends to pioneer the generation and distribution of high quality educational content that will serve both as core text as well as provide an adaptive environment for learning. Copyright ©2009 CK-12 Foundation This work is licensed under the Creative Commons Attribution-Share Alike 3.0 United States License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/3.0/us/ or send a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California, 94105, USA. Contents 1 Cell structure and function dec 16 5 1.1 Lesson 3.1: Introduction to Cells .................................. 5 3 www.ck12.org www.ck12.org 4 Chapter 1 Cell structure and function dec 16 1.1 Lesson 3.1: Introduction to Cells Lesson Objectives • Identify the scientists that first observed cells. • Outline the importance of microscopes in the discovery of cells. • Summarize what the cell theory proposes. • Identify the limitations on cell size. • Identify the four parts common to all cells. • Compare prokaryotic and eukaryotic cells. Introduction Knowing the make up of cells and how cells work is necessary to all of the biological sciences. Learning about the similarities and differences between cell types is particularly important to the fields of cell biology and molecular biology.
    [Show full text]
  • Cell Growth-Regulated Expression of Mammalian MCM5 and MCM6 Genes Mediated by the Transcription Factor E2F
    Oncogene (1999) 18, 2299 ± 2309 ã 1999 Stockton Press All rights reserved 0950 ± 9232/99 $12.00 http://www.stockton-press.co.uk/onc Cell growth-regulated expression of mammalian MCM5 and MCM6 genes mediated by the transcription factor E2F Kiyoshi Ohtani1, Ritsuko Iwanaga1, Masataka Nakamura*,1, Masa-aki Ikeda2, Norikazu Yabuta3, Hiromichi Tsuruga3 and Hiroshi Nojima3 1Human Gene Sciences Center, Tokyo Medical and Dental University, Tokyo 113-8510, Japan 2Department of Developmental Biology, Graduate School of Dentistry, Tokyo Medical and Dental University, Tokyo 113-8549, Japan; 3Department of Molecular Genetics, Research Institute for Microbial Diseases, Osaka University, Suita 565-0871, Japan Initiation of DNA replication requires the function of family (MCM2-7) that have been identi®ed in yeast, MCM gene products, which participate in ensuring that Xenopus, and human. Mcm proteins seem to regulate DNA replication occurs only once in the cell cycle. the initiation at the replication origin where the loading Expression of all mammalian genes of the MCM family of the proteins onto the origin recognition complex is induced by growth stimulation, unlike yeast, and the (ORC) is regulated by Cdc6 and cyclin-dependent mRNA levels peak at G1/S boundary. In this study, we kinases (Donovan et al., 1997; Tanaka et al., 1997). examined the transcriptional activities of isolated human However, the mechanism(s) by which Mcm proteins MCM gene promoters. Human MCM5 and MCM6 control the initiation of DNA replication remains promoters with mutation in the E2F sites failed in unclear. promoter regulation following serum stimulation and Xenopus Mcm proteins seem to be able to access exogenous E2F expression.
    [Show full text]
  • Cell Life Cycle and Reproduction the Cell Cycle (Cell-Division Cycle), Is a Series of Events That Take Place in a Cell Leading to Its Division and Duplication
    Cell Life Cycle and Reproduction The cell cycle (cell-division cycle), is a series of events that take place in a cell leading to its division and duplication. The main phases of the cell cycle are interphase, nuclear division, and cytokinesis. Cell division produces two daughter cells. In cells without a nucleus (prokaryotic), the cell cycle occurs via binary fission. Interphase Gap1(G1)- Cells increase in size. The G1checkpointcontrol mechanism ensures that everything is ready for DNA synthesis. Synthesis(S)- DNA replication occurs during this phase. DNA Replication The process in which DNA makes a duplicate copy of itself. Semiconservative Replication The process in which the DNA molecule uncoils and separates into two strands. Each original strand becomes a template on which a new strand is constructed, resulting in two DNA molecules identical to the original DNA molecule. Gap 2(G2)- The cell continues to grow. The G2checkpointcontrol mechanism ensures that everything is ready to enter the M (mitosis) phase and divide. Mitotic(M) refers to the division of the nucleus. Cell growth stops at this stage and cellular energy is focused on the orderly division into daughter cells. A checkpoint in the middle of mitosis (Metaphase Checkpoint) ensures that the cell is ready to complete cell division. The final event is cytokinesis, in which the cytoplasm divides and the single parent cell splits into two daughter cells. Reproduction Cellular reproduction is a process by which cells duplicate their contents and then divide to yield multiple cells with similar, if not duplicate, contents. Mitosis Mitosis- nuclear division resulting in the production of two somatic cells having the same genetic complement (genetically identical) as the original cell.
    [Show full text]
  • Deciphering Genetic Determinants of Cell Growth by Single-Cell RNA Sequencing Deregulated Growth Is a Hallmark of Human Diseases
    Deciphering genetic determinants of cell growth by single-cell RNA sequencing Deregulated growth is a hallmark of human diseases such as cancer. A wide range of therapeutic approaches target proliferating cells effectively through inhibition of pathways related to growth and division. However, cells can often escape arrest due to the genetic and phenotypic heterogeneity present in cancer cell populations leading to relapse of the disease. Likewise, heterogeneity in gene expression makes treatment of persistent microbial infections an important challenge for human health. Identifying genetic and non-genetic features that can drive individual cells to overcome growth inhibition is therefore required to understand disease progression and resistance. Recent experimental protocols made it possible to characterise the transcriptomes and genotypes of single cells simultaneously. These opened the door to investigate the dynamics and heterogeneity of gene expression in population of cells with variable genotypes. These methods are technically challenging, generate large amounts of complex data, and require the development of state-of-the-art computational methods for their analysis. Yet, when coupled with mathematical modelling of cell physiology, these single cells approaches have an unprecedented potential to unravel complex genetic and gene expression programmes that underlie growth dynamics of cell populations. This project aims at: i) understanding the genetic basis of cell growth under conditions were gene expression or proliferation are compromised by associating high fitness genotypes to transcriptome signatures in single cells, ii) develop computational tools to integrate single-cell and population level genotyping and gene expression data, iii) improve selected aspect of the laboratory single-cell RNA-seq protocol to improve data quality.
    [Show full text]
  • How Genes Work
    Help Me Understand Genetics How Genes Work Reprinted from MedlinePlus Genetics U.S. National Library of Medicine National Institutes of Health Department of Health & Human Services Table of Contents 1 What are proteins and what do they do? 1 2 How do genes direct the production of proteins? 5 3 Can genes be turned on and off in cells? 7 4 What is epigenetics? 8 5 How do cells divide? 10 6 How do genes control the growth and division of cells? 12 7 How do geneticists indicate the location of a gene? 16 Reprinted from MedlinePlus Genetics (https://medlineplus.gov/genetics/) i How Genes Work 1 What are proteins and what do they do? Proteins are large, complex molecules that play many critical roles in the body. They do most of the work in cells and are required for the structure, function, and regulation of thebody’s tissues and organs. Proteins are made up of hundreds or thousands of smaller units called amino acids, which are attached to one another in long chains. There are 20 different types of amino acids that can be combined to make a protein. The sequence of amino acids determineseach protein’s unique 3-dimensional structure and its specific function. Aminoacids are coded by combinations of three DNA building blocks (nucleotides), determined by the sequence of genes. Proteins can be described according to their large range of functions in the body, listed inalphabetical order: Antibody. Antibodies bind to specific foreign particles, such as viruses and bacteria, to help protect the body. Example: Immunoglobulin G (IgG) (Figure 1) Enzyme.
    [Show full text]
  • Anatomy and Physiology Cell Cycle and Cancer Study Guide
    Anatomy and Physiology Cell Cycle and Cancer Study Guide Use this guide to direct your attention toward the information to be covered by the test. 1. Which phase of mitosis has the chromosomes being pulled apart toward opposite ends? 16. What stage is when the nucleus divides? 2. Which stage of cell division involves the forming 17. What stage is when the cytoplasm divides? of two new daughter cells? 18. What is a chromatid? 3. The basic unit of structure and function in the human body is the: 19. What is a centromere? a. cell b. organ c. atom d. tissue e. system 4. Mitosis occurs after what stage of the cell cycle? 20. What are stem cells? How many phases does it have? 21. The process that ensures duplication of DNA molecules during cell reproduction is 5. List in order the phases of mitosis and tell the ___________________________. main events that occur in each phase. 22. Match these events in cell reproduction with the correct description: a. Prophase b. Metaphase 6. What is the centriole and the spindle and what is c. Anaphase their role in cellular reproduction? d. Telophase i. Microtubules shorten and pull chromosomes toward centrioles 7. Draw a diagram for: ii. Chromatin forms chromosomes; a. Prophase nuclear membrane and nucleolus disappear iii. Chromosomes elongate, and b. Metaphase nuclear membranes form around each chromosome set iv. Chromosomes become arranged c. Anaphase midway between centrioles; duplicate parts of chromosomes become separated d. Telophase 23. What is a tumor? Explain what causes it to form. 8. What is the smallest living unit? 24.
    [Show full text]
  • The Cell Cycle: Myths and Realities Renato Baserga1
    [CANCER RESEARCH 50, 6769-6771, November 1, 1990] Perspectives in Cancer Research The Cell Cycle: Myths and Realities Renato Baserga1 Department of Pathology and the Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140 A number of startling discoveries in the past few years have simply overexpression, the regulation of cell growth is affected. given us a picture of the cell cycle that is solidly based on Indeed, even now, despite antioncogenes and yeast genes, one molecular biology and genetics. Growth factors (both stimula cannot disregard protooncogenes in any rational scheme of tory and inhibitory), oncogenes and antioncogenes, the bio animal cell proliferation. The extent of their role may be chemistry of DNA replication, the animal homologues of yeast debatable, but they do have a role. However, their putative cell cycle genes, cyclins, the use of antisense strategies, and growth-regulatory role is based on their relationship to viral many others have opened new vistas to our understanding of transforming genes and not on the fact that they are growth cell cycle controls (1). This perspective, however, is not dedi regulated. cated to a eulogy of these seminal findings; they speak for In the meantime, scores of laboratories (including mine, I themselves. I will, in fact, be the devil's advocate and do the admit) have been picking out, through differential screening of opposite, i.e., have a critical look, not at the findings (they are complementary DNA libraries, an embarrassing number of unarguable), but at some of the conclusions that have been growth-regulated genes.
    [Show full text]
  • GCSE Biology Key Words
    GCSE Biology Key Words Definitions and Concepts for AQA Biology GCSE Definitions in bold are for higher tier only Topic 1- Cell Biology Topic 2 - Organisation Topic 3 – Infection and Response Topic 4 – Bioenergetics Topic 5 - Homeostasis Topic 6 – Inheritance and Variation Topic 7 – Ecology Topic 1: Cell Biology Definitions in bold are for higher tier only Active transport: The movement of substances from a more dilute solution to a more concentrated solution (against a concentration gradient) with the use of energy from respiration. Adult stem cell: A type of stem cell that can form many types of cells. Agar jelly: A substance placed in petri dishes which is used to culture microorganisms on. Cell differentiation: The process where a cell becomes specialised to its function. Cell membrane: A partially permeable barrier that surrounds the cell. Cell wall: An outer layer made of cellulose that strengthens plant cells. Chloroplast: An organelle which is the site of photosynthesis. Chromosomes: DNA structures that are found in the nucleus which are made up of genes. Concentration gradient: The difference in concentration between two areas. Diffusion: The spreading out of the particles of any substance in solution, or particles of a gas, resulting in a net movement from an area of higher concentration to an area of lower concentration.✢ Embryonic stem cell: A type of stem cell that can differentiate into most types of human cells. Eukaryotic cell: A type of cell found in plants and animals that contains a nucleus. Magnification: How much bigger an image appears compared to the original object. Meristematic cells: A type of stem cell that can differentiate into any type of plant cell.
    [Show full text]
  • Glossary of Biotechnology Terms
    GLOSSARY OF BIOTECHNOLOGY TERMS Until recently, command of technical terms among lawyers was largely limited to patent counsel. Now, with the dramatic increase in the interaction between technology and law, there is a generalized need among lawyers for greater agility and familiarity with scientific jargon. This glossary has been compiled as a checklist of common biotechnology terms to aid the scientifically uninitiated practitioner. Special attention has been paid to terms which appear in the accompanying articles by Bertram I. Rowland1 and Adrienne B. Naumann. 2 No attempt, however, has been made to provide a comprehensive biotechnology dictionary. For further technical guidance, please see the accompanying Research 3 Pathfinder. Amino acid - Any Organic com- vaccines, blood, blood components pound containing both an amino and derivatives, or allergenic pro- group and a carboxylic group, bound ducts. as essential components of a protein Biotechnology - Commercial tech- molecule. niques that use living organisms, or Antenatal diagnosis - Diagnosis of substances from these organisms, to a condition before birth. make or modify a product, and Antibody - A protein produced by including techniques used for the the body's immune defense system improvement of the characteristics of that can bind to foreign molecules economically important plants and and eliminate them. animals and for the development of Bacterium - Single-celled organism microorganisms to act on the lacking a nucleus and other struc- environment. tures; useful for cloning genes Cell - The fundamental unit of liv- because of fast growth. Bacteria may ing organisms. The cell is character- exist as free living organisms in soil, ized by an outer wall or membrane water, organic matter, or as parasites which is selectively permeable to in the live bodies of plants, animals nutrients, water, and other com- and other microorganisms.
    [Show full text]
  • Content Outline for Biological Science Section of the MCAT
    Content Outline for Biological Science Section of the MCAT Content Outline for Biological Science Section of the MCAT BIOLOGY MOLECULAR BIOLOGY: ENZYMES AND METABOLISM A. Enzyme Structure and Function 1. Function of enzymes in catalyzing biological reactions 2. Reduction of activation energy 3. Substrates and enzyme specificity B. Control of Enzyme Activity 1. Feedback inhibition 2. Competitive inhibition 3. Noncompetitive inhibition C. Basic Metabolism 1. Glycolysis (anaerobic and aerobic, substrates and products) 2. Krebs cycle (substrates and products, general features of the pathway) 3. Electron transport chain and oxidative phosphorylation (substrates and products, general features of the pathway) 4. Metabolism of fats and proteins MOLECULAR BIOLOGY: DNA AND PROTEIN SYNTHESIS DNA Structure and Function A. DNA Structure and Function 1. Double-helix structure 2. DNA composition (purine and pyrimidine bases, deoxyribose, phosphate) 3. Base-pairing specificity, concept of complementarity 4. Function in transmission of genetic information B. DNA Replication 1. Mechanism of replication (separation of strands, specific coupling of free nucleic acids, DNA polymerase, primer required) 2. Semiconservative nature of replication C. Repair of DNA 1. Repair during replication 2. Repair of mutations D. Recombinant DNA Techniques 1. Restriction enzymes 2. Hybridization © 2009 AAMC. May not be reproduced without permission. 1 Content Outline for Biological Science Section of the MCAT 3. Gene cloning 4. PCR Protein Synthesis A. Genetic Code 1. Typical information flow (DNA → RNA → protein) 2. Codon–anticodon relationship, degenerate code 3. Missense and nonsense codons 4. Initiation and termination codons (function, codon sequences) B. Transcription 1. mRNA composition and structure (RNA nucleotides, 5′ cap, poly-A tail) 2.
    [Show full text]
  • 1 Introduction to Cell Biology
    1 Introduction to cell biology 1.1 Motivation Why is the understanding of cell mechancis important? cells need to move and interact with their environment ◦ cells have components that are highly dependent on mechanics, e.g., structural proteins ◦ cells need to reproduce / divide ◦ to improve the control/function of cells ◦ to improve cell growth/cell production ◦ medical appli- cations ◦ mechanical signals regulate cell metabolism ◦ treatment of certain diseases needs understanding of cell mechanics ◦ cells live in a mechanical environment ◦ it determines the mechanics of organisms that consist of cells ◦ directly applicable to single cell analysis research ◦ to understand how mechanical loading affects cells, e.g. stem cell differentation, cell morphology ◦ to understand how mechanically gated ion channels work ◦ an understanding of the loading in cells could aid in developing struc- tures to grow cells or organization of cells more efficiently ◦ can help us to understand macrostructured behavior better ◦ can help us to build machines/sensors similar to cells ◦ can help us understand the biology of the cell ◦ cell growth is affected by stress and mechanical properties of the substrate the cells are in ◦ understanding mechan- ics is important for knowing how cells move and for figuring out how to change cell motion ◦ when building/engineering tissues, the tissue must have the necessary me- chanical properties ◦ understand how cells is affected by and affects its environment ◦ understand how mechanical factors alter cell behavior (gene expression)
    [Show full text]
  • B-2 the Student Will Demonstrate an Understanding of the Structure and Function of Cells and Their Organelles. Effective June 20
    B-2 The student will demonstrate an understanding of the structure and function of cells and their organelles. B-2.1 Recall the three major tenets of cell theory (all living things are composed of one or more cells; cells are the basic units of structure and function in living things; and all presently existing cells arose from previously existing cells). Taxonomy Level: 1.2-B Remember Conceptual Knowledge Key Concepts: Cell theory Unicellular organism, multicellular organism Previous knowledge: In 5th grade (5-2.1), students recalled the cell as the smallest unit of life and identified its major structures (including cell membrane, cytoplasm, nucleus, and vacuole). In 7th grade, students summarized the structures and functions of the major components of plant and animal cells (including the cell wall, the cell membrane, the nucleus, chloroplasts, mitochondria, and vacuoles) (7-2.1), compared the major components of plant and animal cells (7-2.2), and explained how cellular processes (including respiration, photosynthesis in plants, mitosis, and waste elimination) are essential to the survival of the organism (7-2.4). It is essential for students to know the three major tenets of the cell theory: • All living things are composed of one or more cells. • Cells are the basic unit of structure of all living things. ○ The lowest level of structure capable of performing all the activities of life is the cell. ○ A unicellular organism is composed of one cell and all of life’s activities occur within that single cell. ○ In a multicellular organism, each cell carries on most of the major functions of life.
    [Show full text]