The Co-activator-like Mediator Complex Forms a Molecular Bridge Between Activation Domains and Pol II

Co-activator

the general problem

example of several upstream activators interacting with a single co-activator-like mediator complex Transcription Regulation And Gene Expression in Eukaryotes FS 2016 Graduate Course G2

P. Matthias and RG Clerc Pharmazentrum Hörsaal 2 16h15-18h00

REGULATORY MECHANISMS OF FUNCTION

• synthesized •Protein phosphorylated •Ligand binding •Release inhibitor •Change partner, etc

RG Clerc April 6. 2016 Transcription factors as final effectors of the cellular signaling cascade Regulatory Mechanisms of Transcription Factor Function

Genes X. Lewin B. editor Regulatory Mechanisms of Transcription Factor Function

CREB

FOXO NFAT

Genes X. Lewin B. editor Body plan is constructed through interactions of the developmentally regulated homeotic gene expression anterior early expression posterior late expression high RA response low RA response

hindbrain trunk

Alexander T and Krumlauf R. Ann.Rev.Cell.Dev.Biol: 25_431 (2009) Hoxb transcription factors mRNA distribution along the AP axis

A

staggered expression of the anterior border within somites is a property of the physical ordering along the chromosome: the colinearity Alexander T and Krumlauf R. Ann.Rev.Cell.Dev.Biol: 25_431 (2009) Transcription control of the Hox genes: insight into colinear activation

P A

p p p p a p a p a a a a Tarchini B and Duboule D. Dev.Cell 10_93 (2006) correlation between linear arrangement along the chromosome and spatial transcriptional regulation WT MUT WT MUT WT MUT Regulatory Mechanisms of Transcription Factor Function

CREB

FOXO NFAT

Genes X. Lewin B. editor Activation of TRX following G-Protein Coupled GPCR Ligand Binding CREB (cyclic-AMP Responsive Elements Binding Protein)

Structure of the CREB basic region/ domain (amino acids 285–339) (bZIP) bound to the somatostatin CRE (TGACGTCA) Phosphorylation of CREB at Ser133 Induces Complex Formation With an α-Helical Domain in CBP

KIX CBP-CREB complex Nuclear stress bodies are the main sites of accumulation of HSF1/2 in stressed cells

The Heat Shock Transcription Factor DBD (wHTH)

cgcctcGAAtgTTCgcGAAa -46 hsp70 The Family Across Species

Canonical HSE (multiple adjacent pentanucleotide motifs) cgcctcGAAtgTTCgcGAAa [-46 hsp70] Regulation of the HS Response and the HSF Cycle

•Inert monomer in the cytoplasm and nucleus •Stress induced DNA binding and TA potential (hyperphosphorylation) •Trimerization •HSF binding protein (HSBP1) negatively regulates trimer •Dissociation of trimers •Generation of unactive monomers upon binding of chaperones Hsp70 and Hdj-1 Regulatory Mechanisms of Transcription Factor Function

CREB

FOXO NFAT

Genes X. Lewin B. editor The Nuclear Pore Complex is the Gateway That Regulates the Two-Way Traffic Between the Nucleus and the Rest of the Cell The Nuclear Pore Complex is the Gateway That Regulates the Two-Way Traffic Between the Nucleus and the Rest of the Cell Nucleocytoplasmic Trafficking: Nucleopore Complex and Karyopherins Regulation of FoxO by Nuclear Shuttling in Response to AKT Mediated Phosphorylation Winged-helix family of trx factors are involved in development, metabolism, cell differentiation

Fox=Forkhead box (100AA) Phosporylation stimulates nuclear export (NES) and prevents nuclear import (NLS) Regulation of FoxO by Nuclear Shuttling in Response to AKT Mediated Phosphorylation The activity of FoxO is tightly regulated by post-translational modifications including phosphorylation, acetylation and ubiquitylation Multiple Levels of Control of NFAT Signaling

TCR, IGF, EGF

inhibition

CsA

induction

IL2,IL3,IL4,GMCSF,TNF

TAD Gwack Y. et al. Cell Calcium 42:145-156 Cooperative Binding of Two Unrelated Transcription Factors to Neighboring Sites

Chen L. and Harrison SC. Nature 392:42-48

NF-AT (REL homology domain), AP-1 (Fos-Jun) cooperatively bind a composite DNA site (ARRE from IL-2 promoter) Regulatory Mechanisms of Transcription Factor Function

CREB

FOXO NFAT

Genes X. Lewin B. editor Hormone Dependent Gene Activation by a Homodimeric or Heterodimeric Nuclear Conformational Change of the LBD of Two Related Nuclear Hormone Receptors Upon Ligand Binding Regulatory Mechanisms of Transcription Factor Function

CREB

FOXO NFAT

Genes X. Lewin B. editor The NFκB Paradigm: Signal Induced Degradation of a Cytosolic Inhibitor Which Activates the TF

Phosphorylation dependent release by inhibitor (eg. iκB-α) upon polyubiquitination - proteasomal mediated degradation

Baltimore D. Nature Immunology 12: 683-686 (2011) The NFκB/REL Family and IκB Proteins

NF-kappa B p50 homodimer bound to DNA Müller CW, Harrisson SG and Verdine GL. Nature 373:311-317 The NFκB Paradigm: Signal Induced Degradation of Cytosolic Inhibitor Proteins Which Activates the TF: 25 years on !

TRX factors such as NFκB are final effectors of various cellular signaling cascades Oeckinghaus A. Hayden M. Ghosh S (2011) Nature Immunology 12:695-708 The NFκB patent Regulatory Mechanisms of Transcription Factor Function

CREB

FOXO NFAT

Genes X. Lewin B. editor Helix-Loop-Helix Domains

E box TF 5’CANNTG3’ Structural Classes Helix-Loop-Helix Domains - the DBD is Separated by Nonhelical Loops from the Leu-Zipper Region (Coiled-Coil)

T. Kadesch Cell Growth and Diff.4:49 (1993) bHLH Factors Activity is Modulated by Partner Exchange

bHLH dimers in which both subunits have a basic region can bind DNA; a dimer in which a subunit lacks the basic region (eg Id) cannot bind the promoter regulatory element Regulatory Mechanisms of Transcription Factor Function

CREB

FOXO NFAT

Genes X. Lewin B. editor Cholesterol and Triglyceride Synthesis Pathways Domain Structure of SREBP’s Membrane Bound TF (sterol regulatory element (SRE) binding protein - 5’PyCAPyNPyCAPy3’) Sterol Dependent Two-Steps Proteolytic Cleavage of TF The Sterol Response: Cleavage to Release the Active TF

Brown M. Goldstein JL. Cell 89 (1997) The canonical Wnt–β-catenin pathway

W. Birchmeier. Nature Reviews 8:387-398 (2008) LEF-1/TCF-1

5’ C Y76 C HELIX 3 BASIC C-TERM L6 T M10 M13 T HELIX 2 T G HELIX 1 E28 A A G C 3’ Looking Beyond …

The Joy of Learning is as Indispensable in Study as Breathing is in Life Simone Weil