transcriptional repressor NF-X1; nuclear transcription factor, X box-binding protein 1 (NFX1, NFX2)

Function

• binds to the X-box motif of MHC class II genes & represses their expression
• may play an important role in regulating the duration of an inflammatory response by limiting the period in which MHC class II molecules are induced by interferon-gamma
• isoform 3 binds to the X-box motif of TERT promoter & represses its expression
• ogether with PABPC1 or PABPC4, isoform 1 acts as a coactivator for TERT expression
• mediates E2-dependent ubiquitination
• isoform 3 is polyubiquitinated in the presence of HPV16 E6 protein; which leads to proteasomal degradation
• isoform 1 is not polyubiquitinated
• isoform 1 & isoform 3 interact with human papillomavirus HPV-16 E6 oncoprotein
• isoform 1 interacts with PABPC1 & PABPC4

Structure

• the RING-type Zn+2 finger domain interacts with ubiquitin-conjugating enzyme E2 & facilitates ubiquitination
• belongs to the NFX1 family
• contains 8 NF-X1-type Zn+2 fingers
• contains 1 R3H domain
• contains 1 RING-type Zn+2 finger

Compartment

nucleus

Alternative splicing

named isoforms=3

Expression

induced by IFNG/IFN-gamma

More general terms

• transcriptional silencer (transcriptional repressor)
• ring finger protein
• phosphoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=4799
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:4799
• OMIM: https://mirror.omim.org/entry/603255
• UniProt: http://www.uniprot.org/uniprot/Q12986.html