AT-rich interactive domain-containing protein 4B (ARID domain-containing protein 4B, histone deacetylase complex subunit SAP180, 180 kD Sin3-associated polypeptide, Sin3-associated polypeptide p180, Retinoblastoma-binding protein 1-like 1, breast cancer-associated antigen BRCAA1, ARID4B, BRCAA1, RBBP1L1, RBP1L1, SAP180)

Function

• transcriptional repressor
• role in assembly &/or enzymatic activity of the Sin3A corepressor complex or in mediating interactions between the complex & other regulatory complexes
• component of a Sin3A corepressor complex

Structure

• contains 1 ARID domain involved in stabilizing the mSin3A corepressor complex on DNA
• C-terminus mediates interaction with mSin3A corepressor complex
• N-terminus is involved in transcriptional repression by HDAC-independent mechanisms

Compartment

• nucleus, cytoplasm
• cytoplasmic in breast cancer cells

Alternative splicing

named isoforms=4

Expression

• highly expressed in the testis
• expressed at low levels in the thymus, prostate & ovary

Pathology

• highly expressed in breast cancer, lung cancer, colon cancer, pancreatic cancer & ovarian cancer

More general terms

• transcriptional silencer (transcriptional repressor)
• AT-rich interactive domain-containing protein

Component of

• Sin3A corepressor complex

Database

• UniProt: http://www.uniprot.org/uniprot/Q4LE39.html