Comparative Proteomic Analysis of a Cytosolic Fraction from β3 Integrin-deficient Cells

Cancer Genomics - Proteomics

Jason A. Bush¹  Jeffrey W. Smith¹  F. Patrick Ross²  Yuliang Ma¹  Hideki Kitaura²  Steven L. Teitelbaum² 

[1] Cancer Center and Center on Proteolytic Pathways, Sanford-Burnham Medical Research Institute, La Jolla, CA, U.S.A.Cancer Center and Center on Proteolytic Pathways, Sanford-Burnham Medical Research Institute, La Jolla, CA, U.S.A.Cancer Center and Center on Proteolytic Pathways, Sanford-Burnham Medical Research Institute, La Jolla, CA, U.S.A.;Department of Pathology, Washington University School of Medicine, St. Louis, MO, U.S.A.Department of Pathology, Washington University School of Medicine, St. Louis, MO, U.S.A.Department of Pathology, Washington University School of Medicine, St. Louis, MO, U.S.A.

关键词: Cathepsin B;    integrin;    isotope-coded affinity tags;    protease;    cancer-proteomics;    fractionation;    GeLC-MS;    HEK293 cells;   

DOI  :  

来源: Delinasios GJ CO

【 摘 要 】

Integrins are heterodimeric transmembrane receptors involved in sensing and transmitting informational cues from the extracellular environment to the cell. This study explored sub-proteome changes in response to elimination of the β3 integrin using a knockout murine model. Cleavable isotope-coded affinity tagging (cICAT) in combination with sub-cellular fractionation, multiple dimensions of separation and tandem mass spectrometry (MS/MS) were used to characterize differentially expressed proteins among β3 integrin–/– (β3–/–) mouse embryonic fibroblasts and isogenic wild-type (WT) controls. From a cytosolic protein fraction, 48 proteins were identified, in which expression differed by >1.5-fold. Predominant ontological groups included actin-binding/cytoskeletal proteins and protease/protease inhibitors. Interestingly, β3 integrin expression was inversely correlated with expression of cathepsin B, a lysosomal cysteine protease, as its expression was greater by over 3.5-fold in the β3–/– cells. This inverse correlation was also observed in stable heterologous cells transfected with β3 integrin, where the intracellular expression and activity of cathepsin B was lower compared to control cells. Our data suggests that the composition of the cellular proteome is influenced by integrin expression patterns and reveals a strong functional relationship between β3 integrin and cathepsin B.

【 授权许可】

Unknown