poptosis‐specific protein (ASP 45 kDa) is distinct from human Apg5, the homologue of the yeast autophagic gene apg5
Yung HW., Xue L., Tolkovsky AM.
We have examined whether the apoptosis‐specific protein p45ASP and human Apg5 are identical proteins. Like p45ASP, myc‐hApg5 cross‐reacted with a c‐Jun antibody and ∼50% of myc‐hApg5 was bound to a Triton X‐100‐insoluble fraction in HeLa cells. However, soluble myc‐hApg5 was degraded during apoptosis induced by staurosporine or TNFα/cycloheximide whilst expression of soluble p45ASP was stabilised. Furthermore, myc‐hApg5 degradation was blocked by the caspase inhibitor Boc‐Asp(OMe)FMK whilst p45ASP expression was eliminated. Moreover, myc‐hApg5 (∼32 kDa) never assumed the size of p45ASP (45 kDa). It is therefore likely that p45ASP and human Apg5 are distinct proteins although they do share some common characteristics.