apoptosis-stimulating of p53 protein 2; tumor suppressor p53-binding protein 2; p53-binding protein 2; p53BP2; 53BP2; Bcl2-binding protein; Bbp; renal carcinoma antigen NY-REN-51 (TP53BP2, ASPP2, BBP)

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Function

plays a role in regulation of apoptosis & cell growth
regulates TP53 by enhancing DNA binding & transactivation of TP53 on promoters of proapoptotic genes in vivo
inhibits ability of APPBP1 to conjugate NEDD8 to CUL1, & thus decreases APPBP1 ability to induce apoptosis
impedes cell cycle progression at G2/M
binds to the central domain of TP53 as well as to BCL2
interacts with protein phosphatase 1
interacts with RELA NF-kappa-B subunit; this interaction probably prevents activation of apoptosis, possibly by preventing its interaction with TP53
interacts with APC2 & APPBP1

the ankyrin repeats & the SH3 domain are required for a specific interactions with TP53
belongs to the ASPP family
contains 2 ANK repeats
contains 1 SH3 domain

named isoforms=2
due to Alu sequence insertion that creates a shorter but existing form that may have an alternative function

widely expressed
expressed in spleen, thymus, prostate, testis, ovary, small intestine, colon & peripheral blood leukocyte
reduced expression in breast carcinomas expressing a wild-type TP53 protein
overexpressed in lung cancer cell lines
expressed following DNA damage induced by UV irradiation
down-regulated by wild-type, but not mutant, TP53