Alternative titles; symbols
HGNC Approved Gene Symbol: TCERG1
Cytogenetic location: 5q32 Genomic coordinates (GRCh38) : 5:146,447,330-146,511,961 (from NCBI)
Sune and Garcia-Blanco (1995) demonstrated the existence of a nuclear factor that is a coactivator of the viral protein Tat (see 601409), necessary for activation of the human immunodeficiency virus type 1 (HIV-1) promoter. By affinity purification, functional analysis, and micropeptide sequencing, followed by EST database searching and probing of a HeLa cell cDNA library, Sune et al. (1997) isolated a cDNA encoding this factor, which the authors called CA150. The deduced 1,097-amino acid protein contains motifs found in transcription factors. The sequence begins and ends with proline-rich (48%) regions; it contains 2 N-terminal and 1 C-terminal WWP domains involved in protein-protein interactions, a 76-amino acid glutamine-alanine repeat, previously observed only in nonmammalian transcription factors, followed by a serine-threonine-proline-rich region, a highly charged KE region, a putative nuclear localization signal, and a putative leucine zipper. Northern blot analysis revealed ubiquitous expression of an approximately 4.5-kb transcript. Western blot analysis confirmed that CA150 is a 150-kD protein present in all cell lines tested. GST pull-down and yeast 2-hybrid analyses detected weak or no interaction with Tat. Immunofluorescence analysis localized CA150 in the nucleoplasm, outside the nucleoli. Immunoprecipitation and Western blot analysis showed that CA150 is associated with the RNA polymerase II holoenzyme (see 180660) independent of the presence of Tat. Tat can also associate with the this holoenzyme. Immunodepletion of CA150 from nuclear extracts eliminated Tat-mediated transactivation. On the other hand, overexpression of truncated CA150 decreased Tat-mediated transcriptional activation of the HIV-1 promoter but had little effect on basal transcription. Sune et al. (1997) thus proposed that Tat action is transduced through an RNA polymerase II holoenzyme containing CA150.
Bohne et al. (2000) cloned the cDNA encoding mouse Ca150 which shares 98% sequence identity with the human protein. Northern blot and whole-mount in situ analyses detected expression in all adult and embryo tissues tested.
Sune and Garcia-Blanco (1999) found that CA150 has a selective role in transcription from certain promoters and regulates transcription elongation in a TATA box-dependent fashion. Overexpression of CA150 represses the transcription of the HIV-1 long terminal repeat and of the ITGA4 (192975) promoter.
By radiation hybrid panel analysis, Bohne et al. (2000) mapped the CA150 gene to chromosome 5q31. They mapped the mouse homolog to chromosome 18.
Bohne, J., Cole, S. E., Sune, C., Lindman, B. R., Ko, V. D., Vogt, T. F., Garcia-Blanco, M. A. Expression analysis and mapping of the mouse and human transcriptional regulator CA150. Mammalian Genome 11: 930-933, 2000. [PubMed: 11003711] [Full Text: https://doi.org/10.1007/s003350010162]
Sune, C., Garcia-Blanco, M. A. Transcriptional cofactor CA150 regulates RNA polymerase II elongation in a TATA-box-dependent manner. Molec. Cell. Biol. 19: 4719-4728, 1999. [PubMed: 10373521] [Full Text: https://doi.org/10.1128/MCB.19.7.4719]
Sune, C., Garcia-Blanco, M. A. Transcriptional trans activation by human immunodeficiency virus type 1 Tat requires specific coactivators that are not basal factors. J. Virol. 69: 3098-3107, 1995. [PubMed: 7707538] [Full Text: https://doi.org/10.1128/JVI.69.5.3098-3107.1995]
Sune, C., Hayashi, T., Liu, Y., Lane, W. S., Young, R. A., Garcia-Blanco, M. A. CA150, a nuclear protein associated with the RNA polymerase II holoenzyme, is involved in Tat-activated human immunodeficiency virus type 1 transcription. Molec. Cell. Biol. 17: 6029-6039, 1997. [PubMed: 9315662] [Full Text: https://doi.org/10.1128/MCB.17.10.6029]