TGS1
Description
The TGS1 (trimethylguanosine synthase 1) is a protein-coding gene located on chromosome 8.
Trimethylguanosine synthase is an enzyme encoded by the TGS1 gene in humans. TGS1 has been shown to interact with CREB-binding protein, EED, EP300, MED1, and NCOA6.
TGS1 catalyzes two sequential methylation steps to convert 7-monomethylguanosine (m(7)G) caps of snRNAs and snoRNAs to a 2,2,7-trimethylguanosine (m(2,2,7)G) cap structure. The enzyme exhibits specificity for guanine, and N7 methylation must occur before N2 methylation. Hypermethylation of the m7G cap in U snRNAs leads to their accumulation in nuclear foci, colocalization with coilin, and the formation of canonical Cajal bodies (CBs). TGS1 plays a role in transcriptional regulation.
TGS1 is also known as NCOA6IP, PIMT, PIPMT.