UBN1
Function
Acts as a novel regulator of senescence. Involved in the formation of senescence-associated heterochromatin foci (SAHF), which represses expression of proliferation-promoting genes. Binds to proliferation-promoting genes. May be required for replication-independent chromatin assembly.
Sequence Similarities
Belongs to the ubinuclein family.
Tissue Specificity
Ubiquitous. Also expressed in numerous tumors and cancer cell lines.
Cellular localization
- Nucleus
- Nucleoplasm
- Nucleus
- PML body
- Cell junction
- Tight junction
- Localized as a nuclear speckled-like pattern in proliferating primary fibroblasts. Colocalizes with HIRA, PML and SP100 in PML bodies of senescent cells. Colocalizes with TJP1 and CLDN1. Detected along the upper granular cell layer of epidermis. When overexpressed, accumulates in the nucleus in cells showing defective cytokinesis.
Alternative names
Ubinuclein-1, HIRA-binding protein, Protein VT4, Ubiquitously expressed nuclear protein, UBN1