FIG. 4.

A 40-kDa band corresponding to the catalytic fragment of PKCδ is present in senescent cells. Western blots and indirect immunofluorescence used a polyclonal antibody (sc-937) which detects both full-length PKCδ and catalytic fragment (PKCδ-CF) of PKCδ. (A) Western blot of whole-cell (Total) and nuclear extracts collected from both young (Y) and old (O) quiescent cells. (B) PKCδ immunofluorescence with the sc-937 PKCδ antibody on young (a) and senescent (b) cells (c and d) DAPI staining of panels a and b, respectively. White arrows indicate nuclei in a typical field. A 400× magnification is also shown for young (e) and senescent (f) cells, with DAPI counterstaining (g and h, respectively).