Genetic interaction of the histone chaperone  hip1  +   with double strand break repair genes in  Schizosaccharomyces pombe .
 Schizosaccharomyces pombe    hip1  +    (human HIRA) is a histone chaperone and transcription factor involved in establishment of the centromeric chromatin and chromosome segregation, regulation of histone transcription, and cellular response to stress. We carried out a double mutant genetic screen of  Δhip1  and mutations in double strand break repair pathway. We find that   hip1  +    functions after the MRN complex which initiates resection of blunt double strand break ends but before recruitment of the DNA damage repair machinery. Further, deletion of   hip1  +    partially suppresses sensitivity to DNA damaging agents of mutations in genes involved in Break Induced Replication (BIR), one mechanism of rescue of stalled or collapses replication forks (   rad51  +    ,   cdc27  +    ).  Δhip1  also suppresses mutations in two checkpoint genes (   cds1  +    ,   rad3  +    ) on hydroxyurea a drug that stalls replication forks. Our results show that   hip1  +    forms complex interactions with the DNA double strand break repair genes and may be involved in facilitating communication between damage sensors and downstream factors.
Disbennett WM, Hawk TM, Rollins PD, Nelakurti DD, Lucas BE, McPherson MT, Hylton HM, Petreaca RC