Placing hSSB2 in the Nucleotide Excision Repair pathway — ASN Events
  1. Schedule
  2. Session Ten - Poster Session C
  3. Placing hSSB2 in the Nucleotide Excision Repair pathway

Placing hSSB2 in the Nucleotide Excision Repair pathway (#342)

Adrian X Gimenez 1 , Ben Crossett 2 , Tristan Ocampo 2 , Ruvini Fernando 1 2 , Didier Boucher 3 , Kum Kum Khanna 3 , Liza Cubeddu 1 , Roland Gamsjaeger 1 2
  1. School of Science and Health, Univesity of Western Sydney, Sydney, NSW, Australia
  2. School of Molecular Biosciences, University of Sydney, Sydney , NSW, Australia
  3. Signal Transduction Laboratory, Queensland Institute of Medical Research, Brisbane, Qld, Australia

The Single Stranded DNA Binding (SSB) protein family is ubiquitous across all domains of life and performs critical functions in DNA metabolic processes such as replication, recombination and repair. SSBs bind Single Stranded DNA (ssDNA) that is generated in these processes through the use of highly conserved Oligonucleotide-Binding (OB) domains.  Recently, we reported the identification of two novel human SSBs (hSSB1 and 2), discovered on the basis of their protein sequence homology with the SSB from the archaeon Sulfolubus solfataricus. hSSB1 is an integral component of Double Stranded Break Repair (DSBR), while our data implicate hSSB2 in the Nucleotide Excision Repair (NER) pathway. hSSB2 is upregulated following Ultra Violet (UV) radiation and cells lacking hSSB2 show a decreased survival rate after UV exposure. Mutational analysis of the hSSB2 DNA binding OB domain has established that 3 conserved aromatic residues are essential for ssDNA binding and a further 7 residues contribute to forming the ssDNA binding cleft. We have conducted large-scale affinity pull down experiments using human nuclear cell extracts and hSSB2 as bait to identify novel protein partners of hSSB2 by mass spectrometry. These data show that hSSB2 associates with several DNA repair proteins and complexes. We are currently in the process of systematically testing a selection of these proteins for direct interaction with hSSB2.