Anti-p107/RBL1 Antibody Picoband®

RBL1 (Retinoblastoma-like 1), also known as Cullular Proteins p107, CP107 and 107, is a protein that in humans is encoded by the RBL1 gene. Ewen et al. (1991) used a partial cDNA for human p107 to map the gene to 20q11. by fluorescence in situ hybridization. Huppi et al. (1996) found that the mouse Rbl1 gene maps to the distal end of chromosome 2, as does also the E2f1 gene. The protein encoded by this gene is similar in sequence and possibly function to the product of the retinoblastoma 1 (RB1) gene. The RB1 gene product is a tumor suppressor protein that appears to be involved in cell cycle regulation, as it is phosphorylated in the S to M phase transition and is dephosphorylated in the G1 phase of the cell cycle. Both the RB1 protein and the product of this gene can form a complex with adenovirus E1A protein and SV40 Large T-antigen, with the SV40 large T-antigen binding only to the unphosphorylated form of each protein. In addition, both proteins can inhibit the transcription of cell cycle genes containing E2F binding sites in their promoters. Due to the sequence and biochemical similarities with the RB1 protein, it is though that the protein encoded by this gene may also be a tumor suppressor. Two transcript variants encoding different isoforms have been found for this gene.

Key regulator of entry into cell division. ly involved in heterochromatin formation by maintaining overall chromatin structure and, in particular, that of constitutive heterochromatin by stabilizing histone methylation. Recruits and targets histone methyltransferases SUV420H1 and SUV420H2, leading to epigenetic transcriptional repression. Controls histone H4 'Lys-20' trimethylation. Probably acts as a transcription repressor by recruiting chromatin-modifying enzymes to promoters. Potent inhibitor of E2F-mediated trans-activation. Forms a complex with adenovirus E1A and with SV40 large T antigen. May bind and modulate functionally certain cellular proteins with which T and E1A compete for pocket binding. May act as a tumor suppressor.

1. Ewen, M. E., Xing, Y., Lawrence, J. B., Livingston, D. M.Molecular cloning, chromosomal mapping, and expression of the cDNA for p107, a retinoblastoma gene product-related protein.Cell 66: 1155-1164, 1991. 2. Huppi, K., Siwarski, D., Mock, B. A., Dosik, J., Hamel, P. A.Molecular cloning, chromosomal mapping, and expression of the mouse p107 gene.Mammalian Genome 7: 353-355, 1996. 3. Kim, K. K., Soonpaa, M. H., Wang, H., Field, L. J.Developmental expression of p107 mRNA and evidence for alternative splicing of the p107 (RBL1) gene product.Genomics 28: 520-529, 1995.

Store at -20°C for one year from date of receipt. After reconstitution, at 4°C for one month. It can also be aliquotted and stored frozen at -20°C for six months. Avoid repeated freeze-thaw cycles.