RHNO1
Description
The RHNO1 (RAD9-HUS1-RAD1 interacting nuclear orphan 1) is a protein-coding gene located on chromosome 12.
RHNO1 plays a crucial role in DNA repair, particularly during mitosis. It is involved in microhomology-mediated end-joining (MMEJ), an alternative DNA repair pathway that operates during mitosis to mend double-strand breaks arising in the S phase. RHNO1 facilitates the recruitment of polymerase theta (POLQ) to these DNA damage sites, promoting their repair. This recruitment occurs after RHNO1 accumulates in M-phase and undergoes phosphorylation by PLK1. Beyond its role in MMEJ, RHNO1 also participates in the DNA damage response (DDR) signaling pathway, specifically in response to genotoxic stresses such as ionizing radiation (IR). During the S phase, RHNO1 is recruited to DNA damage sites through its interactions with the 9-1-1 cell-cycle checkpoint response complex and TOPBP1. This recruitment is dependent on the ATR protein. RHNO1 is essential for the G1 to S phase transition and contributes to the stimulation of CHEK1 phosphorylation.
RHNO1 is also known as C12orf32, HKMT1188, RHINO.