Hct1

Hct1 is a gene and protein designation used in several model organisms to denote a chromatin-associated factor implicated in histone handling during DNA replication and repair. The name Hct1 is derived from histone chaperone transfer 1, though the exact functional annotation can vary by species. In the literature, Hct1 is commonly described as a component that helps coordinate the delivery of histones to sites of new DNA synthesis and participates in chromatin assembly processes.

In studied systems, Hct1 functions as a chromatin assembly factor that facilitates the incorporation of newly synthesized histones onto DNA, coordinating with histone chaperone complexes such as CAF-1 and FACT. By promoting proper nucleosome reassembly after replication or repair, Hct1 contributes to genome stability and plays a role in regulating transcription through modulation of chromatin structure and accessibility at gene promoters.

Localization and structure for Hct1 are generally nuclear. The protein is predicted to be around 40–60 kilodaltons and often contains coiled-coil motifs or other interaction domains that enable binding to histones and partner chaperone proteins. Its activity is influenced by cell-cycle cues and post-translational modifications that tune its affinity for histones and chromatin.

Evolutionarily, Hct1 is conserved across many eukaryotes, though the degree of essentiality varies by organism. Loss-of-function mutations typically cause replication stress sensitivity, slower growth, and altered gene expression profiles, highlighting its role in maintaining chromatin integrity during DNA synthesis and repair. See also: histone chaperones, CAF-1, FACT.