Alternative titles; symbols
HGNC Approved Gene Symbol: RBBP5
Cytogenetic location: 1q32.1 Genomic coordinates (GRCh38): 1:205,086,142-205,121,978 (from NCBI)
See RBBP1 (180201). By direct screening of cDNA expression libraries using purified RB1 (614041) as a probe, Saijo et al. (1995) isolated distinct clones for cellular proteins that bind to the RB1 protein. The total nucleotide sequence of 1 of these clones, RBBP5, which the authors designated RBQ3, was found to encode a protein of 66 kD localized in the nucleus.
Saijo et al. (1995) found that the RBBP5 protein preferentially binds to underphosphorylated RB protein. The region used for binding to this protein was mapped to the E1A-binding pocket B of pRB, which has sequence similarity to the general transcription factor TFIIB (189963).
RBBP5 is a component of the mammalian SET1A (611052)/SET1B (611055) histone H3-Lys4 methyltransferase complexes (Lee et al., 2007).
Li et al. (2016) demonstrated that a minimized human RBBP5-ASH2L (604782) heterodimer is the structural unit that interacts with and activates all MLL family histone methyltransferases (MLL1, 159555; MLL2, 602113; MLL3, 606833; MLL4, 606834; SET1A, 611052; SET1B, 611055). Their structural, biochemical, and computational analyses revealed a 2-step activation mechanism of MLL family proteins. Li et al. (2016) concluded that their findings provided unprecedented insights into the common theme and functional plasticity in complex assembly and activity regulation of MLL family methyltransferases, and also suggested a universal regulation mechanism for most histone methyltransferases.
Using PCR analysis on a human/hamster hybrid cell panel and chromosomal fluorescence in situ hybridization, Saijo et al. (1995) mapped the RBBP5 gene to 1q32.
Lee, J. H., Tate, C. M., You, J. S., Skalnik, D. G. Identification and characterization of the human Set1B histone H3-Lys4 methyltransferase complex. J. Biol. Chem. 282: 13419-13428, 2007. [PubMed: 17355966] [Full Text: https://doi.org/10.1074/jbc.M609809200]
Li, Y., Han, J., Zhang, Y., Cao, F., Liu, Z., Li, S., Wu, J., Hu, C., Wang, Y., Shuai, J., Chen, J., Cao, L., Li, D., Shi, P., Tian, C., Zhang, J., Dou, Y., Li, G., Chen, Y., Lei, M. Structural basis for activity regulation of MLL family methyltransferases. Nature 530: 447-452, 2016. [PubMed: 26886794] [Full Text: https://doi.org/10.1038/nature16952]
Saijo, M., Sakai, Y., Kishino, T., Niikawa, N., Matsuura, Y., Morino, K., Tamai, K., Taya, Y. Molecular cloning of a human protein that binds to the retinoblastoma protein and chromosomal mapping. Genomics 27: 511-519, 1995. [PubMed: 7558034] [Full Text: https://doi.org/10.1006/geno.1995.1084]