Cirhin (UTP4)

Cirhin is a WD40 repeat-containing protein encoded by the UTP4 (formerly CIRH1A) gene, primarily localized in the nucleolus [UniProt: P58061]. It functions as a critical component of the t-UTP subcomplex within the small subunit (SSU) processome, which is essential for the initial stages of pre-ribosomal RNA processing and ribosome biogenesis [PubMed: 20439433]. This complex is required for the transcription of rDNA and the subsequent processing of the 47S pre-rRNA [PubMed: 12145751]. Mutations in the Cirhin gene, specifically the R565W substitution, are the primary cause of North American Indian Childhood Cirrhosis (NAIC), an autosomal recessive intrahepatic cholestasis [OMIM: 607456]. NAIC is characterized by neonatal jaundice, progressing to biliary cirrhosis and portal hypertension in childhood [PubMed: 12145751]. While Cirhin is not currently a target for any approved pharmacological agents, its role in ribosome assembly makes it a subject of study in genetic liver diseases and cellular growth regulation. Understanding its structural role in the SSU processome provides insights into the pathophysiology of ribosomopathies and potential gene therapy approaches for NAIC. The protein's essential nature in basic cellular machinery suggests that any therapeutic modulation would require high specificity to avoid systemic toxicity.

Other names

UTP4CIRH1ANorth American Indian childhood cirrhosis proteinWD repeat-containing protein 4TEX292

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