HUS1 checkpoint clamp component (HUS1)

HUS1 checkpoint clamp component (HUS1) is an evolutionarily conserved protein that forms a heterotrimeric DNA sliding clamp with RAD9 and RAD1, collectively known as the 9-1-1 complex[2][4][5][1]. This complex is structurally and functionally analogous to proliferating cell nuclear antigen (PCNA) and is centrally involved in the cellular response to DNA damage[1][2][3][4][5][6]. Upon DNA damage occurrence, the 9-1-1 complex is loaded onto chromatin by the RAD17–RFC clamp loader at sites of DNA lesions, particularly at 5'-recessed DNA ends[2][5]. Its primary biological roles include acting as a platform for recruiting and regulating DNA repair enzymes, stimulating several activities critical for long-patch base excision repair, and linking DNA damage signals to cell cycle arrest via checkpoint kinase pathways[2][5][6]. Dysfunction or mutations in HUS1 are linked to genetic instability, tumorigenesis, and hereditary repair disorders such as Fanconi anemia and some forms of Noonan syndrome[2]. Note: - There are no approved drugs that directly target HUS1 or the 9-1-1 complex, and it is generally classified as a DNA repair/checkpoint protein, not as a druggable target in the conventional sense as for kinases, GPCRs, or classic receptors[2][6]. - HUS1 is not a receptor, enzyme, transporter, or transcription factor, but rather a structural DNA clamp protein critical for DNA damage response signaling. - No direct biomarkers or drugs are currently associated with selective patient targeting or efficacy monitoring for HUS1. - Therapeutic modulation might carry significant risk due to the fundamental role of HUS1 in maintaining genomic stability[2]. Summary: HUS1 is a core DNA damage checkpoint protein forming a critical part of the 9-1-1 clamp, required for proper DNA repair and cell cycle regulation in response to genomic insult[2][1][4][5][6].

Other names

Checkpoint protein HUS1hHUS1hus1+-like proteinHUS1 checkpoint homologhus1

Drugs would theoretically modulate DNA damage checkpoint activation or DNA repair response by affecting chromatin loading of the 9-1-1 complex or modulating interaction with kinase effector pathways