Chromosomal localization, structure, single-nucleotide polymorphisms, and expression of the human H-protein gene of the glycine cleavage system (GCSH), a candidate gene for nonketotic hyperglycinemia.

Abstract

Nonketotic hyperglycinemia (NKH) is an inborn error of metabolism caused by deficiency in the glycine cleavage system (GCS); this system consists of four individual constituents, P-, T-, H-, and L-proteins. Several mutations have been identified in P- and T-protein genes, but not in the H-protein gene (GCSH), despite the presence of case reports of H-protein deficiency. To facilitate the mutational and functional analyses of GCSH, we isolated and characterized a human p1-derived artificial chromosome (PAC) clone encoding GCSH. GCSH spanned 13.5kb and consisted of five exons. Using the PAC clone as a probe, we mapped GCSH to chromosome 16q24 by fluorescence in situ hybridization. The transcription initiation site was determined by the oligonucleotide-cap method, and potential binding sites for several transcriptional factors were found in the 5' upstream region. Direct sequencing analysis revealed five single-nucleotide polymorphisms. The expression profiles of P-, T-, and H-protein mRNAs were studied by dot-blot analysis, using total RNA from various human tissues. GCSH was expressed in all 29 tissues examined, while T-protein mRNA was detected in 27 of the 29 tissues. In contrast, the P-protein gene was expressed in a limited number of tissues, such as liver, kidney, brain, pituitary gland, and thyroid gland, suggesting distinct transcriptional regulation of each GCS constituent.

• Authors: S Kure, K Kojima, T Kudo, K Kanno, Y Aoki, Y Suzuki, T Shinka, Y Sakata, K Narisawa, Y Matsubara
• Journal: Journal of human genetics (J Hum Genet) Vol. 46 Issue 7 Pg. 378-84 ( 2001) ISSN: 1434-5161 [Print] England
• PMID: 11450847 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• RNA, Messenger
• Amino Acid Oxidoreductases
• Glycine

Topics

• Alleles
• Amino Acid Oxidoreductases (genetics, metabolism)
• Base Sequence
• Chromosome Mapping
• Chromosomes, Human, Pair 16 (genetics)
• Cloning, Molecular
• Exons
• Glycine (blood, metabolism)
• Humans
• Hyperglycinemia, Nonketotic (enzymology, genetics)
• In Situ Hybridization, Fluorescence
• Introns
• Molecular Sequence Data
• Polymorphism, Single Nucleotide (genetics)
• RNA, Messenger (genetics, metabolism)