SSRP1

Domain

The HMG box DNA-binding domain mediates DNA-binding. It has both affinity and specificity for DNA damaged globally with cisplatin.

Function

Component of the FACT complex, a general chromatin factor that acts to reorganize nucleosomes. The FACT complex is involved in multiple processes that require DNA as a template such as mRNA elongation, DNA replication and DNA repair. During transcription elongation the FACT complex acts as a histone chaperone that both destabilizes and restores nucleosomal structure. It facilitates the passage of RNA polymerase II and transcription by promoting the dissociation of one histone H2A-H2B dimer from the nucleosome, then subsequently promotes the reestablishment of the nucleosome following the passage of RNA polymerase II. The FACT complex is probably also involved in phosphorylation of 'Ser-392' of p53/TP53 via its association with CK2 (casein kinase II). Binds specifically to double-stranded DNA and at low levels to DNA modified by the antitumor agent cisplatin. May potentiate cisplatin-induced cell death by blocking replication and repair of modified DNA. Also acts as a transcriptional coactivator for p63/TP63.

Post-translational modifications

Phosphorylated by CK2 following UV but not gamma irradiation. Phosphorylation inhibits its DNA-binding activity.

Ubiquitinated. Polyubiquitinated following caspase cleavage resulting in degradation of the N-terminal ubiquitinated part of the cleaved protein.

Sumoylated.

Sequence Similarities

Belongs to the SSRP1 family.

Cellular localization

• Nucleus
• Nucleus
• Nucleolus
• Chromosome
• Colocalizes with RNA polymerase II on chromatin. Recruited to actively transcribed loci.

Alternative names

FACT80, SSRP1, FACT complex subunit SSRP1, Chromatin-specific transcription elongation factor 80 kDa subunit, Facilitates chromatin transcription complex 80 kDa subunit, Facilitates chromatin transcription complex subunit SSRP1, Recombination signal sequence recognition protein 1, Structure-specific recognition protein 1, T160, FACT 80 kDa subunit, FACTp80, hSSRP1

Database links

swissprot:Q08945 omim:604328 entrezGene:6749 entrezGene:100413716