Detection of a proteolytic cleavage product of endogenous full-length Slp2a in the absence of phosphatase inhibitors. YT cell lines expressing the TAP-active form of Rab27a (Q) or the TAP-inactive form of Rab27a (T) and untransfected YTs (YT) were lysed in the presence or absence of phosphatase inhibitor. Lysates were then immunoprecipitated with IgG beads. Lysates and precipitates (IPs) were analyzed by Western blot for the presence of cleaved or full-length forms of Slp2a using a rabbit antibody raised against the Slp2a SHD domain. Equally, the presence of TAP mutants Rab27a was detected using an anti-Rab27a. Western blot analysis of PI3K was used as a loading control.