TAF5L Background Information TFIID is a general transcription factor that initiates preinitiation complex as-sembly through direct interaction with the TATA promoter element. Functioning as a multisubunit complex consisting of a small TATA-binding polypeptide and other TBP-associated factors (TAFs), TFIID mediates promoter responses to various transcriptional activators and repressors. TAF5L (TAF5-like RNA polymerase II p300/CBP-associated factor-associated factor 65 kDa subunit 5L), also known as PAF65B, is a 589 amino acid protein that localizes to the nucleus and contains six WD repeats. Existing as a component of the PCAF histone acetylase complex, TAF5L interacts with a number of TAFs and, via this interaction, plays a role in histone acetylation and transcription initiation. Defects in the gene encoding TAF5L, which is expressed as multiple alternatively spliced isoforms, are associated with the pathogenesis of type I diabetes.
