Methylcrotonyl-CoA carboxylase subunit 2 (MCCC2)

Methylcrotonyl-CoA carboxylase subunit 2 (MCCC2) is the beta subunit of a biotin-dependent mitochondrial enzyme (3-methylcrotonyl-CoA carboxylase) that is critical for the catabolism of leucine and isovaleric acid. MCCC2 functions as part of a heterodimeric enzyme complex (with MCCC1 encoding the alpha subunit), catalyzing the carboxylation of 3-methylcrotonyl-CoA to 3-methylglutaconyl-CoA—an essential step in amino acid breakdown. Deficiency of MCCC2 due to genetic mutations results in the metabolic disorder 3-methylcrotonylglycinuria, manifesting as organic aciduria, vomiting, metabolic acidosis, and potential neurologic sequelae. Recent studies show MCCC2 is upregulated in several cancers and contributes to tumor cell proliferation, migration, and invasion, possibly by mediating mitochondrial dynamics, telomere maintenance, and supporting glycolysis. MCCC2 forms a complex with telomere-binding TRF2 and interacts with telomeric RNA, suggesting a potential role in genomic stability beyond its classical metabolic function. It is a useful biomarker in colorectal cancer and an important enzyme for cellular metabolism and disease.

Other names

Methylcrotonoyl-CoA carboxylase beta chain, mitochondrialMCCBMCCase subunit betaMCCCβ3-methylcrotonyl-CoA carboxylase 23-methylcrotonyl-CoA carboxylase non-biotin-containing subunit3-methylcrotonyl-CoA:carbon dioxide ligase subunit betamethylcrotonoyl-CoA carboxylase betabiotin carboxylasemethylcrotonoyl-Coenzyme A carboxylase 2 (beta)testicular secretory protein Li 29

No drugs directly targeting this molecule have been reported. Mechanisms for experimental therapies would involve enzyme replacement, gene therapy, metabolic modulation (dietary/vitamin approaches), or manipulation of mitochondrial metabolism.