CLSPNClaspin is a protein that in humans is encoded by the CLSPN gene.FunctionXenopus claspin is an essential upstream regulator of checkpoint kinase 1 and triggers a checkpoint arrest of the cell cycle in the presence of DNA templates in Xenopus egg extracts. The human gene appears to be the homolog Xenopus claspin and its function has not been determined.InteractionsCLSPN has been shown to interact with: BRCA1, CDC45, CHEK1, POLE, RAD17, and USP7.