SAP30L
Domain
The zinc-finger domain mediates direct interaction with DNA and phosphoinositol phosphates (phosphoinositol 3-phosphate, phosphoinositol 4-phosphate and phosphoinositol 5-phosphate) (PubMed:26609676). In vitro oxydation causes reversible disulfide bond formation between Cys residues in the zinc-finger domain and reversible loss of zinc ion binding (PubMed:26609676).
Function
Isoform 1
Functions as a transcription repressor, probably via its interaction with histone deacetylase complexes (PubMed:16820529, PubMed:18070604). Involved in the functional recruitment of the class 1 Sin3-histone deacetylase complex (HDAC) to the nucleolus (PubMed:16820529). Binds DNA, apparently without sequence-specificity, and bends bound double-stranded DNA (PubMed:19015240). Binds phosphoinositol phosphates (phosphoinositol 3-phosphate, phosphoinositol 4-phosphate and phosphoinositol 5-phosphate) via the same basic sequence motif that mediates DNA binding and nuclear import (PubMed:19015240, PubMed:26609676).
Isoform 2
Functions as a transcription repressor; isoform 2 has lower transcription repressor activity than isoform 1 and isoform 3.
Isoform 3
Functions as a transcription repressor; its activity is marginally lower than that of isoform 1.
Sequence Similarities
Belongs to the SAP30 family.
Tissue Specificity
Detected in brain and ovary, and at lower levels in heart, small intestine, lung, kidney, skeletal muscle, stomach and spleen (at protein level) (PubMed:18070604). Ubiquitous; expressed in all tissues tested with highest levels in testis (PubMed:14680513).
Cellular localization
- Isoform 1
- Nucleus
- Nucleolus
- Isoform 2
- Nucleus
- Nucleolus
- Isoform 3
- Nucleus
- Nucleolus
Alternative names
NS4ATP2, SAP30L, Histone deacetylase complex subunit SAP30L, HCV non-structural protein 4A-transactivated protein 2, Sin3 corepressor complex subunit SAP30L, Sin3-associated protein p30-like