ExpSup: Pragmin Induces c-Src Activation

Note: For more detailed and accurate information, please read the cited reference.

• Overexpression of Pragmin in the AGS cell line leads to increased c-Src activity (Safari et al., 2011) 
  • Note: c-Src is a member of SFK (Src family kinase). 
  • Experiment details: 
    • Cell line: AGS cell line transiently expressing Myc-tagged Pragmin
    • Method: Western blotting to  measure the level of Y416-phosphorylated c-Src (active c-Src) and Y530-phosphorylated c-Src (inactive c-Src) using specific antibodies.

• Downregulation of Pragmin in the AGS cell line leads to inactivation of c-Src (Safari et al., 2011) 
  • Experiment details: 
    • Cell line: AGS cell line transfected with Pragmin-specific siRNA
    • Method: Western Blotting to  measure the level of Y416-phosphorylated c-Src (active c-Src) using specific antibodies.

• Explanation: 
  • Safari et al., 2011 suggest that Pragmin sequesters Csk in the cytoplasm, making Csk unavailable at the membrane to phosphorylate and inactivate c-Src.
  • Csk inactivates c-Src by phosphorylating a consensus tyrosine residue (Y530 in human c-Src)

References:

• Safari et al., 2011. Mammalian Pragmin regulates Src family kinases via the Glu-Pro-Ile-Tyr-Ala (EPIYA) motif that is exploited by bacterial effectors. Proc Natl Acad Sci USA. 108(36), 14938-14943. PMID-21873224; Full Text: pnas,  PMC