SAGE-Hindawi Access to Research Journal of Amino Acids Volume 2011, Article ID 207691, 13 pages doi:10.4061/2011/207691 Review Article Small Changes Huge Impact: The Role of Protein Posttranslational Modifications in Cellular Homeostasis and Disease Tejaswita M. Karve 1 and Amrita K. Cheema2 1 Department of Biochemistry, Cellular & Molecular Biology, Lombardi Comprehensive Cancer Center, Georgetown University School of Medicine, 3900 Reservoir Road, NW, Washington DC 20057, USA 2 Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University School of Medicine, Washington, DC 20057, USA Correspondence should be addressed to Amrita K. Cheema,
[email protected] Received 23 February 2011; Accepted 18 April 2011 Academic Editor: Zulfiqar Ahmad Copyright © 2011 T. M. Karve and A. K. Cheema. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Posttranslational modifications (PTMs) modulate protein function in most eukaryotes and have a ubiquitous role in diverse range of cellular functions. Identification, characterization, and mapping of these modifications to specific amino acid residues on proteins are critical towards understanding their functional significance in a biological context. The interpretation of proteome data obtained from the high-throughput methods cannot be deciphered unambiguously without a priori knowledge of protein modifications. An in-depth understanding of protein PTMs is important not only for gaining a perception of a wide array of cellular functions but also towards developing drug therapies for many life-threatening diseases like cancer and neurodegenerative disorders. Many of the protein modifications like ubiquitination play a decisive role in various drug response(s) and eventually in disease prognosis.