RelA-associated inhibitor (inhibitor of ASPP protein, protein iASPP, PPP1R13B-like protein, NFkB-interacting protein 1, PPP1R13L, IASPP, NKIP1, PPP1R13BL, RAI)

Function

• role in regulation of apoptosis & transcription via interaction with NF-kappa-B & p53/TP53 proteins
• blocks transcription of HIV-1 virus by inhibiting the action of both NF-kappa-B & SP1
• inhibits p53/TP53 function via preventing association of p53/TP53 & ASPP1 or ASPP2, thus suppresses apoptosis (putative)
• interacts with RELA NF-kappa-B subunit & with SP1 via its C-terminus

Structure

• belongs to the ASPP family
• contains 2 ANK repeats contains 1 SH3 domain

Compartment

• isoform 1: cytoplasm, nucleus (predominantly cytoplasmic)
  • N-terminal region of isoform 1 is required for cytoplasmic localization
• isoform 2: nucleus

Alternative splicing

named isoforms=2

Expression

• expressed in heart, placenta, prostate > brain, liver, skeletal muscle, testis, peripheral blood leukocyte

Pathology

• defects in PPP1R13L may be a cause of breast cancers
• overexpressed in many patients with breast cancer & expressing a wild-type p53/TP53 protein

More general terms

• phosphoprotein

Database

• OMIM: https://mirror.omim.org/entry/607463
• UniProt: http://www.uniprot.org/uniprot/Q8WUF5.html