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    CMAHP cytidine monophospho-N-acetylneuraminic acid hydroxylase, pseudogene [ Homo sapiens (human) ]

    Gene ID: 8418, updated on 10-Dec-2024

    Summary

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    Official Symbol
    CMAHPprovided by HGNC
    Official Full Name
    cytidine monophospho-N-acetylneuraminic acid hydroxylase, pseudogeneprovided by HGNC
    Primary source
    HGNC:HGNC:2098
    See related
    Ensembl:ENSG00000293489 MIM:603209; AllianceGenome:HGNC:2098
    Gene type
    pseudo
    RefSeq status
    VALIDATED
    Organism
    Homo sapiens
    Lineage
    Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo
    Also known as
    CMAH; CSAH
    Summary
    Sialic acids are terminal components of the carbohydrate chains of glycoconjugates involved in ligand-receptor, cell-cell, and cell-pathogen interactions. The two most common forms of sialic acid found in mammalian cells are N-acetylneuraminic acid (Neu5Ac) and its hydroxylated derivative, N-glycolylneuraminic acid (Neu5Gc). Studies of sialic acid distribution show that Neu5Gc is not detectable in normal human tissues although it was an abundant sialic acid in other mammals. Neu5Gc is, in actuality, immunogenic in humans. The absense of Neu5Gc in humans is due to a deletion within the human gene CMAH encoding cytidine monophosphate-N-acetylneuraminic acid hydroxylase, an enzyme responsible for Neu5Gc biosynthesis. Sequences encoding the mouse, pig, and chimpanzee hydroxylase enzymes were obtained by cDNA cloning and found to be highly homologous. However, the homologous human cDNA differs from these cDNAs by a 92-bp deletion in the 5' region. This deletion, corresponding to exon 6 of the mouse hydroxylase gene, causes a frameshift mutation and premature termination of the polypeptide chain in human. It seems unlikely that the truncated human hydroxylase mRNA encodes for an active enzyme explaining why Neu5Gc is undetectable in normal human tissues. Human genomic DNA also shows evidence of this deletion which does not occur in the genomes of African great apes. Nonetheless, the CMAH gene maps to 6p21.32 in humans and great apes indicating that mutation of the CMAH gene occurred following human divergence from chimpanzees and bonobos. [provided by RefSeq, Jul 2008]
    Expression
    Ubiquitous expression in skin (RPKM 10.5), lung (RPKM 9.3) and 23 other tissues See more
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    Genomic context

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    See CMAHP in Genome Data Viewer
    Location:
    6p22.3
    Exon count:
    14
    Annotation release Status Assembly Chr Location
    RS_2024_08 current GRCh38.p14 (GCF_000001405.40) 6 NC_000006.12 (25081067..25138392, complement)
    RS_2024_08 current T2T-CHM13v2.0 (GCF_009914755.1) 6 NC_060930.1 (24946777..25004128, complement)
    RS_2024_09 previous assembly GRCh37.p13 (GCF_000001405.25) 6 NC_000006.11 (25081295..25138620, complement)

    Chromosome 6 - NC_000006.12Genomic Context describing neighboring genes Neighboring gene RHO family interacting cell polarization regulator 2 Neighboring gene uncharacterized LOC102724765 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 24162 Neighboring gene RNA, 7SL, cytoplasmic 334, pseudogene Neighboring gene argininosuccinate synthetase 1 pseudogene 1 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 24163 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 24164 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 24165 Neighboring gene ReSE screen-validated silencer GRCh37_chr6:25059321-25059634 Neighboring gene OCT4-NANOG-H3K27ac hESC enhancer GRCh37_chr6:25061721-25062289 Neighboring gene uncharacterized LOC124901282 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 24166 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 24167 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 24168 Neighboring gene OCT4-NANOG-H3K4me1 hESC enhancer GRCh37_chr6:25153639-25154343 Neighboring gene nucleoporin 50 pseudogene 2 Neighboring gene CANT1 pseudogene 1

    Genomic regions, transcripts, and products

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    Go to nucleotide: Graphics FASTA GenBank

    Expression

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    • Project title: HPA RNA-seq normal tissues
    • Description: RNA-seq was performed of tissue samples from 95 human individuals representing 27 different tissues in order to determine tissue-specificity of all protein-coding genes
    • BioProject: PRJEB4337
    • Publication: PMID 24309898
    • Analysis date: Wed Apr 4 07:08:55 2018

    Bibliography

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    Related articles in PubMed

    1. Phylogenetic Distribution of CMP-Neu5Ac Hydroxylase (CMAH), the Enzyme Synthetizing the Proinflammatory Human Xenoantigen Neu5Gc. Peri S, et al. Genome Biol Evol, 2018 Jan 1. PMID 29206915, Free PMC Article
    2. The molecular basis for the absence of N-glycolylneuraminic acid in humans. Irie A, et al. J Biol Chem, 1998 Jun 19. PMID 9624188
    3. CMP-N-Acetylneuraminic acid hydroxylase is exclusively inactive in humans. Irie A, et al. Biochem Biophys Res Commun, 1998 Jul 20. PMID 9675135
    4. A structural difference between the cell surfaces of humans and the great apes. Muchmore EA, et al. Am J Phys Anthropol, 1998 Oct. PMID 9786333
    5. N-glycolylneuraminic acid deficiency in humans. Varki A. Biochimie, 2001 Jul. PMID 11522390

    See all (22) citations in PubMed

    GeneRIFs: Gene References Into Functions

    What's a GeneRIF?
    1. GGTA1/CMAH knockout pig samples had increased relative amounts of high-mannose, incomplete, and xylosylated N-linked glycans
      Title: N-linked glycan profiling of GGTA1/CMAH knockout pigs identifies new potential carbohydrate xenoantigens.
    2. Metabolically reintroducing sialic acid to human T cells (which by mutation of CMAH occurring 2 million years ago lack natural sialic acid) blunts proliferation and activation.
      Title: Enhanced T cell function in a mouse model of human glycosylation.
    3. Observational study of gene-disease association. (HuGE Navigator)
      Title: Investigation of genetic susceptibility factors for human longevity - a targeted nonsynonymous SNP study.
    4. Data show that CMAH gene expression is significantly upregulated in the adult stem cell populations studied, both of hematopoietic and mesenchymal origin, and identify CMAH as a novel stem cell marker.
      Title: Human CMP-N-acetylneuraminic acid hydroxylase is a novel stem cell marker linked to stem cell-specific mechanisms.
    Submit: New GeneRIF Correction

    Phenotypes

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    Review eQTL and phenotype association data in this region using PheGenI

    Variation

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    See studies and variants in dbVar

    See Variation Viewer (GRCh37.p13)

    See Variation Viewer (GRCh38)

    Interactions

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    Products Interactant Other Gene Complex Source Pubs Description

    General gene information

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    Markers

    Other Names

    • CMP-N-acetylneuraminic acid hydroxylase
    • CMP-Neu5Ac hydroxylase
    • CMP-NeuAc hydroxylase
    • CMP-sialic acid hydroxylase
    • cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMP-N-acetylneuraminate monooxygenase)(pseudogene)

    Gene Ontology Provided by GOA

    Function Evidence Code Pubs
    enables CMP-N-acetylneuraminate monooxygenase activity IBA
    Inferred from Biological aspect of Ancestor
    more info
    		  
    NOT enables CMP-N-acetylneuraminate monooxygenase activity NAS
    Non-traceable Author Statement
    more info
    		 PubMed 
    Process Evidence Code Pubs
    involved_in CMP-N-acetylneuraminate metabolic process IBA
    Inferred from Biological aspect of Ancestor
    more info
    		  
    involved_in regulation of Wnt signaling pathway IMP
    Inferred from Mutant Phenotype
    more info
    		 PubMed 
    Component Evidence Code Pubs
    is_active_in cytoplasm IBA
    Inferred from Biological aspect of Ancestor
    more info
    		  
    located_in cytoplasm IDA
    Inferred from Direct Assay
    more info
    		 PubMed 
    located_in cytoskeleton IDA
    Inferred from Direct Assay
    more info
    		 PubMed 
    located_in membrane IDA
    Inferred from Direct Assay
    more info
    		 PubMed 
    located_in nucleus IDA
    Inferred from Direct Assay
    more info
    		 PubMed 

    NCBI Reference Sequences (RefSeq)

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    RefSeqs maintained independently of Annotated Genomes

    These reference sequences exist independently of genome builds. Explain

    These reference sequences are curated independently of the genome annotation cycle, so their versions may not match the RefSeq versions in the current genome build. Identify version mismatches by comparing the version of the RefSeq in this section to the one reported in Genomic regions, transcripts, and products above.

    RNA

    1. NR_002174.2 RNA Sequence

      Status: VALIDATED

      Description
      Transcript Variant: This variant (1) represents the longer transcript.
      Source sequence(s)
      AF074480, BG536615, CA312822
      Related
      ENST00000761679.1

    2. NR_027626.1 RNA Sequence

      Status: VALIDATED

      Description
      Transcript Variant: This variant (2) contains alternate 5' and 3' exons, compared to variant 1.
      Source sequence(s)
      AL133268, BC032500, DA976765
      Related
      ENST00000761682.1

    RefSeqs of Annotated Genomes: GCF_000001405.40-RS_2024_08

    The following sections contain reference sequences that belong to a specific genome build. Explain

    Reference GRCh38.p14 Primary Assembly

    Genomic

    1. NC_000006.12 Reference GRCh38.p14 Primary Assembly

      Range
      25081067..25138392 complement
      Download
      GenBank, FASTA, Sequence Viewer (Graphics)

    Alternate T2T-CHM13v2.0

    Genomic

    1. NC_060930.1 Alternate T2T-CHM13v2.0

      Range
      24946777..25004128 complement
      Download
      GenBank, FASTA, Sequence Viewer (Graphics)

    Suppressed Reference Sequence(s)

    The following Reference Sequences have been suppressed. Explain

    1. NM_003570.2: Suppressed sequence

      Description
      NM_003570.2: This RefSeq record was removed by NCBI staff. Contact info@ncbi.nlm.nih.gov for further information.
    Nucleotide Protein
    Heading Accession and Version
    Protein Accession Links
    GenPept Link UniProtKB Link
    Q9Y471.4 GenPept UniProtKB/Swiss-Prot:Q9Y471

    Gene LinkOut

    The following LinkOut resources are supplied by external providers. These providers are responsible for maintaining the links.

    Chemical Information
    Molecular Biology Databases
    Research Materials