Ataxin-7-like protein 3B (ATXN7L3B)

Ataxin-7-like protein 3B (ATXN7L3B) is a cytoplasmic protein that regulates gene expression and histone modification by binding to ENY2, interfering with the nuclear functions of the deubiquitinase (DUB) module of the SAGA complex[1][3]. This module includes ENY2, ATXN7, ATXN7L3, and USP22. ATXN7L3B affects USP22 DUB activity toward histones indirectly by changing ENY2 localization, decreasing nuclear ENY2-ATXN7L3 interaction, and destabilizing ATXN7L3. ATXN7L3B is highly expressed in ER-positive breast cancer cells, regulates estrogen receptor functions, and suppresses migration[2]. It is also implicated in promoting cancer stemness in hepatocellular carcinoma[6]. Although previously described as a long noncoding RNA (lnc-SCA7), ATXN7L3B in humans encodes a functional 97-amino acid protein[2]. Mutations or alterations in ATXN7L3B have been associated with neurodegenerative disease (spinocerebellar ataxia type 7) and several cancers.

Other names

ATXN7L3BA7L3BQ96GX2hQ96GX2552889lnc-SCA7putative ataxin-7-like protein 3B

Modulation of cancer stemness (metformin downregulation of ATXN7L3B reduces stemness in hepatocellular carcinoma); Indirect modulation of histone deubiquitination and estrogen receptor signaling (ATXN7L3B regulates ER target gene expression via SAGA complex activity in breast cancer)