Profiling the activity of G proteins in patient-derived tissues by rapid affinity-capture of signal transduction proteins (GRASP).
The next phase in molecular medicine will require the ability to identify signal transduction events inside a cell, in the biologic context of the disease-host interface and at a given point in time. New technologies are needed to profile the activity of these signaling pathways in patient tissue rather than cultured cell lines since the tumor-host microenvironment influences the cellular proteome. We introduce such a technology, rapid affinity capture of signaling proteins (GRASP), to investigate the activity of signaling pathways from patient-derived carcinomas and benign epithelial surfaces and apply it to studying important signaling events in ovarian carcinoma. During the progression from benign ovarian epithelium to invasive carcinoma, there is loss of repression of Rho A as evidenced by its dissociation from its inhibitor, Rho Guanine Nucleotide Dissociation Inhibitor (RhoGDI). GRASP is more informative than simply profiling transcript or protein levels. Furthermore, GRASP coupled with mass spectrometry allowed us to identify a protein-binding partner of RhoGDI, demonstrating the power of this technology in the discovery of potentially novel protein-protein interactions. GRASP represents an advance in the field of proteomics as it detects protein interactions present in cells as they exist in their native tissue microenvironment.
Berman
David M
DM
Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. bermand@mail.nih.gov
Shih
Ie-Ming
IeM
Burke
Lorri-Anne
LA
Veenstra
Timothy D
TD
Zhao
Yingming
Y
Conrads
Thomas P
TP
Kwon
Sung Won
SW
Hoang
Van
V
Yu
Li-Rong
LR
Zhou
Ming
M
Kurman
Robert J
RJ
Petricoin
Emanuel F
EF
Liotta
Lance A
LA
D002277:Carcinoma / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism; D005260:Female; D019204:GTP-Binding Proteins / Q000737:chemistry*; D006801:Humans; D008163:Luminescent Measurements; D008274:Magnesium / Q000494:pharmacology; D008280:Magnetics; D013058:Mass Spectrometry / Q000379:methods; D010051:Ovarian Neoplasms / Q000378:metabolism; D010053:Ovary / Q000378:metabolism; D020543:Proteome; D040901:Proteomics / Q000379:methods*; D015398:Signal Transduction; D020741:rho GTP-Binding Proteins / Q000378:metabolism
D020543:Proteome; D019204:GTP-Binding Proteins; D020741:rho GTP-Binding Proteins; D008274:Magnesium