Tbio RBL1 Retinoblastoma-like protein 1

Protein Summary

Description

Key regulator of entry into cell division. Directly 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 KMT5B and KMT5C, 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. 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 thought 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. [provided by RefSeq, Jul 2008]

Uniprot Accession IDs

• P28749
• A8K2W5
• Q4VXA0
• Q8N5K6
• Q9H1L5
• Q9H1M1

Gene Name

• RBL1

Ensembl ID

• ENST00000344359
• ENSP00000343646
• ENSG00000080839
• ENST00000373664
• ENSP00000362768

Symbol

• PRB1
• p107
• CP107

Knowledge Table

Most Knowledge About	Knowledge Value (0 to 1 scale)
hub protein	0.97
viral protein	0.93
protein domain	0.92
histone modification site profile	0.89
virus	0.89

Protein Classes

PANTHER Classes

Protein / Transcription Factor / Retinoblastoma-like Protein 1

Protein / Nucleic Acid Binding / Retinoblastoma-like Protein 1

DTO Classes

Protein / Nucleic Acid Binding / Retinoblastoma-like Protein 1

IDG Development Level Summary

Tdark

These are targets about which virtually nothing is known. They do not have known drug or small molecule activities
- AND - satisfy two or more of the following criteria:

Pubmed score: 422.4   (req: < 5)

Gene RIFs: 31   (req: <= 3)

Antibodies: 382   (req: <= 50)

Tbio

These targets do not have known drug or small molecule activities
- AND - satisfy two or more of the following criteria:

Pubmed score: 422.4   (req: >= 5)

Gene RIFs: 31   (req: > 3)

Antibodies: 382   (req: > 50)

- OR - satisfy the following criterion:

Gene Ontology Terms: 16

Tchem

Target has at least one ChEMBL compound with an activity cutoff of < 30 nM - AND - satisfies the preceding conditions

Active Ligand: 0

Tclin

Target has at least one approved drug - AND - satisfies the preceding conditions

Active Drug: 0