RESEARCH ARTICLE
Signal Transduction Pathways in Chronic Inflammatory Autoimmune Disease: Small GTPases
Kris A Reedquist*, Paul P Tak
Article Information
Identifiers and Pagination:
Year: 2012Volume: 6
Issue: Suppl 2
First Page: 259
Last Page: 272
Publisher ID: TORJ-6-259
DOI: 10.2174/1874312901206010259
Article History:
Received Date: 4/4/2011Revision Received Date: 19/6/2012
Acceptance Date: 21/6/2012
Electronic publication date: 7/9/2012
Collection year: 2012

open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
Abstract
Ras superfamily small GTPases represent a wide and diverse class of intracellular signaling proteins that are highly conserved during evolution. These enzymes serve as key checkpoints in coupling antigen receptor, growth factor, cytokine and chemokine stimulation to cellular responses. Once activated, via their ability to regulate multiple downstream signaling pathways, small GTPases amplify and diversify signaling cascades which regulate cellular proliferation, survival, cytokine expression, trafficking and retention. Small GTPases, particularly members of the Ras, Rap, and Rho family, critically coordinate the function and interplay of immune and stromal cells during inflammatory respones, and increasing evidence indicates that alterations in small GTPase signaling contribute to the pathological behavior of these cell populations in human chronic inflammatory diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Here, we review how Ras, Rap, and Rho family GTPases contribute to the biology of cell populations relevant to human chronic inflammatory disease, highlight recent advances in understanding how alterations in these pathways contribute to pathology in RA and SLE, and discuss new therapeutic strategies that may allow specific targeting of small GTPases in the clinic.