ncb2, not co-repressor

[ValWood]

SPBC30D10.02

new term (and for binding partner)

[ValWood]

these are GTFs

• [x] ncb2 transcription corepressor Ncb2 (predicted) -> transcription corepressor activity (GO:0003714)

[ValWood]

Hi @colinlog sorry to bother you, I know you are super busy. I can't remember where we discussed that this was not a co-repressor. Do you have a reference I can use, or can you point me to the transcription group discussion? I remember we talked about it but I did not do it soon enough that I remembered the critical information.

[colinlog]

Dear Val, According to the classic literature summarized by Koster et al (PMID:25957681) this is NC2b. Together with NC2a, that protein is a 'negative regulator of the TBP GTF. This would make nc2b a 'negative regulator of GTF GO:0016251' but that GO term does not exist... Importantly, it may not be a negatively-acting factor for TBP in vivo, in that it may rather be part of the cycle of RNA polymerase II initiation + RNA polymerase II promoter clearance. In fact that was the conclusion that we reached in April, we decided to annotate nc2b as a GTF (GO:0016251).

Furthermore, It appears that this protein is a subunit of the ATAC complex in metazoa, which is considered a coregulator (GO:0003712, more specifically a coactivator (GO:0003713)).

The best would be to annotate it to GTF GO:0016251 as it is clearly involved in TBP biochemistry and TBP is the epitomy of a GTF. Colin

[ValWood]

Thank, I remember the discussion now!