TATA-box binding protein like 2 is a protein that in humans is encoded by the TBPL2gene.[5]
The TBPL2 protein is also known as TBP-related factor 3 (TRF3) and TATA binding protein 2 (TBP2). The protein was independently discovered in three laboratories as a vertebrate-specific family member of TATA-binding protein (TBP).
[6][7][8]
Orthologs have been identified in mouse, frog (Xenopus tropicalis) and fish (Danio rerio). Whereas the TBP gene is found in all eukaryotes, TBPL2 is only found in vertebrates.[9][10]
Similar to TBP, TBPL2 can bind to the TATA box. It interacts with other general transcription factors such as TFIIA and TFIIB and promotes transcription initiation in vitro.[7][8]
The core domain, which mediates this binding to DNA, shows 95% identity between TBP and TBPL2.[10] The N-terminal domain of TBPL2 exhibits only limited homology to that of TBP.
Early reports mistakenly suggested a wide expression pattern of TBPL2. The main site of expression, however, is the oocyte, where it acts as a replacement factor for TBP.[8][11][12][13]
Knockout mice are normal and viable, but females are not fertile in the absence of TBPL2 due to a defect in folliculogenesis. [14]
TBPL2 has also been identified as a factor necessary to reprogram stem cells to oocytes.[15]