Identification of a tankyrase-binding motif shared by IRAP, TAB182, and human TRF1 but not mouse TRF1. NuMA contains this RXXPDG motif and is a novel tankyrase partner.

摘要: Tankyrase-1 and -2 are closely related poly(ADP-ribose) polymerases that use an ankyrin-repeat domain to bind diverse proteins, including TRF (telomere-repeat binding factor)-1, IRAP (insulin-responsive aminopeptidase), TAB182 (182-kDa tankyrase-binding protein). TRF1 allows tankyrase regulate telomere dynamics in human cells, whereas presumably the targeting of IRAP. The mechanism by which binds proteins has not been investigated. Herein we describe a novel RXXPDG motif shared IRAP, TAB182, mediates their tankyrases. Interestingly, mouse lacks this thus does either tankyrase-1 or -2. Using ankyrin as bait yeast two-hybrid screen, also found six candidate partners, nuclear/mitotic apparatus protein (NuMA). We verified NuMA RXXPDG-mediated partner suggest interaction contributes known colocalization at mitotic spindle poles.