Chromosome 9 open reading frame 78 (C9orf78)

Chromosome 9 open reading frame 78 (C9orf78) is a conserved, intrinsically unstructured protein involved in alternative pre-mRNA splicing. It promotes usage of the upstream 3′-splice site at alternative NAGNAG splice sites and regulates exon skipping, with its function in humans appearing specific to certain alternative splicing events[3][4]. C9orf78 interacts with spliceosomal components, notably the BRR2 ATPase and PRPF8, and UV-crosslinks to U5 snRNA[3][1][5]. Although overexpressed in some cancers, including hepatocellular carcinoma, and considered a marker for favorable prognosis in certain renal cancers, its precise therapeutic targeting is not established[3][1]. The protein also exhibits a subpopulation that localizes to kinetochores in mitosis, suggesting a role in chromosome segregation and cell division, and its depletion can cause mitotic defects in vitro[1][5]. Despite its potential as a biomarker in cancer, no drugs are currently known to interact with C9orf78, nor is it established as a direct therapeutic target at this time.

Other names

Splicing factor C9orf78HCA59HSPC220CSU2TLS1bA409K20.3Hepatocellular carcinoma-associated antigen 59Telomere length and silencing protein 1 homolog