HGNC Approved Gene Symbol: APOC4
Cytogenetic location: 19q13.32 Genomic coordinates (GRCh38): 19:44,942,237-44,945,496 (from NCBI)
Allan et al. (1995) identified and characterized a previously unreported human gene located within the previously known cluster of apolipoprotein genes on chromosome 19: APOE (107741), APOC1 (107710), and APOC2 (608083). On the basis of its location and its properties, the new gene was designated APOC4. RNase protection analysis indicated relatively low apoC-IV mRNA levels in human liver, compared to apoC-II mRNA levels. The predicted apoC-IV protein sequence, comprising 127 amino acid residues, contains a putative 25-residue signal peptide and 2 potential amphipathic alpha-helical domains. Amino acid sequence comparisons indicated a limited homology between apoC-IV and either apoC-I or apoC-II. Its hepatic expression and predicted protein structure are characteristics of other genes in the chromosome 19 cluster and indicate that APOC4 is a member of the apolipoprotein gene family.
By nucleotide sequence analysis of genomic DNA and liver cDNA clones, Allan et al. (1995) determined that the APOC4 gene is 3.3 kb and consists of 3 exons and 2 introns. Its 3-prime terminus lies 555 bp upstream of APOC2, giving the 2 genes the same transcriptional orientation. The promoter of the APOC4 gene lacks a typical TATA box, consistent with an apparent heterogeneity in transcription start sites.
Allan, C. M., Walker, D., Segrest, J. P., Taylor, J. M. Identification and characterization of a new human gene (APOC4) in the apolipoprotein E, C-I, and C-II gene locus. Genomics 28: 291-300, 1995. [PubMed: 8530039] [Full Text: https://doi.org/10.1006/geno.1995.1144]