C9orf64 Explained

C9orf64 (Chromosome 9 open reading frame 64) is a gene located on chromosome 9, that in humans encodes the protein queuosine salvage protein.^[1] The function and biological process of the queuosine salvage protein is a queuosine-nucleotide N-glycosylase/hydrolase (QNG1) that releases queuine from Q-5'-monophosphate, and this activity is required forthe salvage of queuine from exogenous Queuosine by S. pombe and HeLacells.^[2] Some evidence from orthologs indicates it may be involved in tRNA processing and recycling. The most common mRNA contains 4 coding exons, and it has 2 additional alternatively spliced exons. C9orf64 has been found in 5 different splice variants.^[3]

Expression of this gene is highest in the duodenum and small intestine, and it is also expressed in 24 other tissues.^[4]

22 variants have been annotated in the NIH Database, ClinVar, linked to disease conditions such as seizures, developmental delay, and muscular hypotonia.^[5]

Protein

Queuosine salvage protein is 341 amino acids long with a molecular weight of 39,029 daltons and an isoelectric point of 5.61. It is a member of the DUF2419 superfamily.^{[6] [7]} The DUF position on the human protein is from amino acid 53 to 341.^[6] Bioinformatic tools at ExPASy predicted a second peroxisomal targeting signal.^[8] Crystal structures of wild-type humanQNG1 and QNG1 in complex with queuine have been deposited with theProtein Data Bank under accession numbers 7UGK and 8DL3.^{[9] [10]} The DUF position on the human protein is from amino acid 53 to 341.^[6]

Gene locus

C9orf64 is located on chromosome 9q21.32.^[1] The genes closest to C9orf64 on the long arm of chromosome 9 include GKAP1, KIF27, HNRNPK, RMI1, and a MicroRNA MIR7-1.^[11]

Homology

C9orf64 is only found in eukaryotes. Orthologs have been found from primates to fungi and plants.

Further reading

• Hung SH, Elliott GI, Ramkumar TR, Burtnyak L, McGrenaghan CJ, Alkuzweny S, Quaiyum S, Iwata-Reuyl D, Pan X, Green BD, Kelly VP, de Crécy-Lagard V, Swairjo MA. Structural basis of Qng1-mediated salvage of the micronutrient queuine from queuosine-5'-monophosphate as the biological substrate. . Nucleic Acids Research . 51 . 2 . 935–951 . 2023 . 36610787 . 10.1093/nar/gkac1231 . free . 9881137 .
• Cai LY, Abe M, Izumi S, Imura M, Yasugi T, Ushijima T . Identification of PRTFDC1 silencing and aberrant promoter methylation of GPR150, ITGA8 and HOXD11 in ovarian cancers . Life Sciences . 80 . 16 . 1458–65 . 2007 . 17303177 . 10.1016/j.lfs.2007.01.015 .
• Sweetser DA, Peniket AJ, Haaland C, Blomberg AA, Zhang Y, Zaidi ST, Dayyani F, Zhao Z, Heerema NA, Boultwood J, Dewald GW, Paietta E, Slovak ML, Willman CL, Wainscoat JS, Bernstein ID, Daly SB . Delineation of the minimal commonly deleted segment and identification of candidate tumor-suppressor genes in del(9q) acute myeloid leukemia . Genes, Chromosomes and Cancer . 44 . 3 . 279–91 . 2005 . 16015647 . 10.1002/gcc.20236 . 25536746 . free .

Notes and References

1. Web site: Entrez Gene: C9orf64.
2. NCBI: PubMed. 2023 . 36610787 . Hung . S. H. . Elliott . G. I. . Ramkumar . T. R. . Burtnyak . L. . McGrenaghan . C. J. . Alkuzweny . S. . Quaiyum . S. . Iwata-Reuyl . D. . Pan . X. . Green . B. D. . Kelly . V. P. . De Crécy-Lagard . V. . Swairjo . M. A. . Nucleic Acids Research . 51 . 2 . 935–951 . 10.1093/nar/gkac1231 . 9881137 .
3. Web site: NCBI: AceView.
4. Web site: C9orf64 chromosome 9 open reading frame 64 [Homo sapiens (human)] - Gene - NCBI]. www.ncbi.nlm.nih.gov. 2018-06-02.
5. Web site: C9orf64[gene] - ClinVar - NCBI]. ClinVar. www.ncbi.nlm.nih.gov. 2018-06-02.
6. Web site: Sanger: Welcome Trust Institute. https://web.archive.org/web/20121103145023/http://pfam.sanger.ac.uk/family/PF10343.3. dead. 2012-11-03.
7. Web site: BLAST results for LOC84267 [Homo sapiens]].
8. Web site: ExPASy Proteomics Server.
9. Web site: PDB:7UGK.
10. Web site: PDB:8DL3.
11. Web site: Entrez Gene: C9orf64 chromosome 9 open reading frame 64 [Homo sapiens]].