High impact information on Ssrp1

• Accordingly, SSRP1 was unable to stimulate DeltaN-p63-mediated residual luciferase activity and apoptosis in cells [1].
• Thus, Ssrp1 appears to encode nonredundant and p53-independent functions that are essential for cell viability [2].
• To assist in the functional analysis of SSRP1, the Ssrp1 gene was targeted in murine embryonic stem cells, and the mutation was introduced into the germ line [2].
• The high-mobility-group box protein SSRP1/T160 is essential for cell viability in day 3.5 mouse embryos [2].
• The high-mobility-group (HMG) SSRP1 protein is a member of a conserved chromatin-remodeling complex (FACT/DUF/CP) implicated in DNA replication, basal and regulated transcription, and DNA repair [2].

Biological context of Ssrp1

• Using restriction fragment length polymorphisms, the T160 gene was mapped at the proximal end of mouse chromosome 2 [3].
• A search of a data base revealed that the T160 protein has significant sequence homology (56%) to the nonhistone chromosomal protein HMG1 within the C-terminal region of 80 amino acids [3].
• Furthermore, while T160 expression does not change during the cell cycle, it is dramatically down-regulated when cells begin to differentiate, as highlighted in C2C12 myoblasts and myotubes [4].
• Last, tissue distribution by Western blotting analysis showed that the T160 protein is expressed in various murine tissues in addition to those of lymphoid origin [5].
• The HMG protein T160 colocalizes with DNA replication foci and is down-regulated during cell differentiation [4].

Anatomical context of Ssrp1

• The disappearance of T160 nuclear staining in multinucleated myotubes is shown [4].
• We show that T160 is a phosphoprotein broadly conserved from yeast to mammals, with a high level of expression in all the cell lines tested and in tissues containing a high degree of proliferating cells [4].
• Indirect immunofluorescence analysis by confocal laser microscopy revealed that T160 distribution in the cell nucleus is not uniform, and focus-like staining was observed [4].

Associations of Ssrp1 with chemical compounds

• In this study, the T160 protein or truncated forms made soluble through denaturing and renaturing cycles in urea were successfully used in gel-shift experiments showing that T160 binds to cruci-form or linear duplex DNA with no apparent sequence specificity [5].
• Bacterially expressed p40MO15 was phosphorylated mainly on serine 170 (a p34cdc2 phosphorylation site) by mitotic cell extracts, but mutation of S170 to alanine did not affect the activation of p40MO15, whereas mutation of T176 (the equivalent site to T161/T160 in p34cdc2/p33cdk2) abolished the activation of P40MO15 [6].

Other interactions of Ssrp1

• The RAG locus-associated gene T160 is located 1.8 kb upstream of the transcription start site of mouse P2X3 gene [7].
• Both Daxx and SSRP1 were released from heterochromatin early in G(2) phase and Daxx was recruited back to ND10, indicating that both proteins localize to heterochromatin during a very short temporal window of the cell cycle [8].
• Identification of a cDNA for SSRP1, an HMG-box protein, by interaction with the c-Myc oncoprotein in a novel bacterial expression screen [9].

Analytical, diagnostic and therapeutic context of Ssrp1

• Impaired growth of T160- cells was mainly related to two mechanisms: i) decreased rates of cell proliferation at normal serum concentration; and ii) occurrence of cell death by apoptosis at low serum concentration, as demonstrated by both flow cytometry and microscopy [10].

References