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Reliable, easy-to-read patient information on common medical conditions โ written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Apolipoprotein C1
Introduction
Apolipoprotein C-I is a protein component of lipoproteins that in humans is encoded by the APOC1 gene.[1][2]
Function
Function
The protein encoded by this gene is a member of the apolipoprotein C family. This gene is expressed primarily in the liver, and it is activated when monocytes differentiate into macrophages. A pseudogene of this gene is located 4 kb downstream in the same orientation, on the same chromosome. This gene is mapped to chromosome 19, where it resides within an apolipoprotein gene cluster. Alternatively spliced transcript variants have been found for this gene, but the biological validity of some variants has not been determined.[3]
Apolipoprotein C1 has a length of 57 amino acids normally found in plasma and responsible for the activation of esterified lecithin cholesterol with an important role in the exchange of esterified cholesterol between lipoproteins and in removal of cholesterol from tissues. Its main function is inhibition of CETP, probably by altering the electric charge of HDL molecules.
During fasting (like other apolipoprotein C), it is found primarily within HDL, while after a meal it is found on the surface of other lipoproteins. When proteins rich in triglycerides like chylomicrons and VLDL are broken down, this apoprotein is transferred again to HDL. It is one of the most positively charged proteins in the human body.
Interactive pathway map
Interactive pathway map
Click on genes, proteins and metabolites below to link to respective articles. [ยง 1]
- โ The interactive pathway map can be edited at WikiPathways: “Statin_Pathway_WP430”.
References
References
- โ Tata F, Henry I, Markham AF, Wallis SC, Weil D, Grzeschik KH, Junien C, Williamson R, Humphries SE (1985). “Isolation and characterisation of a cDNA clone for human apolipoprotein CI and assignment of the gene to chromosome 19”. Hum. Genet. 69 (4): 345โ9. doi:10.1007/BF00291654. PMIDย 2985493.
- โ Smit M, van der Kooij-Meijs E, Frants RR, Havekes L, Klasen EC (January 1988). “Apolipoprotein gene cluster on chromosome 19. Definite localization of the APOC2 gene and the polymorphic Hpa I site associated with type III hyperlipoproteinemia”. Hum. Genet. 78 (1): 90โ3. doi:10.1007/BF00291243. PMIDย 2892779.
- โ “Entrez Gene: APOC1 apolipoprotein C-I”.
External links
External links
- Human APOC1 genome location and APOC1 gene details page in the UCSC Genome Browser.
Further reading
Further reading
- Shulman RS, Herbert PN, Wehrly K, Fredrickson DS (1975). “Thf complete amino acid sequence of C-I (apoLp-Ser), an apolipoprotein from human very low density lipoproteins”. J. Biol. Chem. 250 (1): 182โ90. PMIDย 166984.
- Lauer SJ, Walker D, Elshourbagy NA, et al. (1988). “Two copies of the human apolipoprotein C-I gene are linked closely to the apolipoprotein E gene”. J. Biol. Chem. 263 (15): 7277โ86. PMIDย 2835369.
- Smit M, van der Kooij-Meijs E, Woudt LP, et al. (1988). “Exact localization of the familial dysbetalipoproteinemia associated HpaI restriction site in the promoter region of the APOC1 gene”. Biochem. Biophys. Res. Commun. 152 (3): 1282โ8. doi:10.1016/S0006-291X(88)80424-8. PMIDย 2897845.
- Davison PJ, Norton P, Wallis SC, et al. (1986). “There are two gene sequences for human apolipoprotein CI (apo CI) on chromosome 19, one of which is 4 kb from the gene for apo E”. Biochem. Biophys. Res. Commun. 136 (3): 876โ84. doi:10.1016/0006-291X(86)90414-6. PMIDย 3013172.
- Myklebost O, Rogne S (1986). “The gene for human apolipoprotein CI is located 4.3 kilobases away from the apolipoprotein E gene on chromosome 19”. Hum. Genet. 73 (4): 286โ9. doi:10.1007/BF00279087. PMIDย 3017837.
- Jackson RL, Sparrow JT, Baker HN, et al. (1974). “The primary structure of apolopoprotein-serine”. J. Biol. Chem. 249 (16): 5308โ13. PMIDย 4369340.
- Knott TJ, Robertson ME, Priestley LM, et al. (1984). “Characterisation of mRNAs encoding the precursor for human apolipoprotein CI”. Nucleic Acids Res. 12 (9): 3909โ15. doi:10.1093/nar/12.9.3909. PMCย 318798. PMIDย 6328444.
- Servillo L, Brewer HB, Osborne JC (1981). “Evaluation of the mixed interaction between apolipoproteins A-II and C-I equilibrium sedimentation”. Biophys. Chem. 13 (1): 29โ38. doi:10.1016/0301-4622(81)80022-1. PMIDย 6789904.
- Curry MD, McConathy WJ, Fesmire JD, Alaupovic P (1981). “Quantitative determination of apolipoproteins C-I and C-II in human plasma by separate electroimmunoassays”. Clin. Chem. 27 (4): 543โ8. PMIDย 7471419.
- Rozek A, Buchko GW, Cushley RJ (1995). “Conformation of two peptides corresponding to human apolipoprotein C-I residues 7-24 and 35-53 in the presence of sodium dodecyl sulfate by CD and NMR spectroscopy”. Biochemistry. 34 (22): 7401โ8. doi:10.1021/bi00022a013. PMIDย 7779782.
- Maruyama K, Sugano S (1994). “Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides”. Gene. 138 (1โ2): 171โ4. doi:10.1016/0378-1119(94)90802-8. PMIDย 8125298.
- Trask B, Fertitta A, Christensen M, et al. (1993). “Fluorescence in situ hybridization mapping of human chromosome 19: cytogenetic band location of 540 cosmids and 70 genes or DNA markers”. Genomics. 15 (1): 133โ45. doi:10.1006/geno.1993.1021. PMIDย 8432525.
- Kamino K, Yoshiiwa A, Nishiwaki Y, et al. (1996). “Genetic association study between senile dementia of Alzheimer’s type and APOE/C1/C2 gene cluster”. Gerontology. 42 Suppl 1: 12โ9. doi:10.1159/000213820. PMIDย 8804993.
- Rozek A, Buchko GW, Kanda P, Cushley RJ (1998). “Conformational studies of the N-terminal lipid-associating domain of human apolipoprotein C-I by CD and 1H NMR spectroscopy”. Protein Sci. 6 (9): 1858โ68. doi:10.1002/pro.5560060906. PMCย 2143781. PMIDย 9300485.
- Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, et al. (1997). “Construction and characterization of a full length-enriched and a 5′-end-enriched cDNA library”. Gene. 200 (1โ2): 149โ56. doi:10.1016/S0378-1119(97)00411-3. PMIDย 9373149.
- Halushka MK, Fan JB, Bentley K, et al. (1999). “Patterns of single-nucleotide polymorphisms in candidate genes for blood-pressure homeostasis”. Nat. Genet. 22 (3): 239โ47. doi:10.1038/10297. PMIDย 10391210.
- Freitas EM, Zhang WJ, Lalonde JP, et al. (1999). “Sequencing of 42kb of the APO E-C2 gene cluster reveals a new gene: PEREC1”. DNA Seq. 9 (2): 89โ100. doi:10.3109/10425179809086433. PMIDย 10520737.
- Gautier T, Masson D, de Barros JP, et al. (2001). “Human apolipoprotein C-I accounts for the ability of plasma high density lipoproteins to inhibit the cholesteryl ester transfer protein activity”. J. Biol. Chem. 275 (48): 37504โ9. doi:10.1074/jbc.M007210200. PMIDย 10978346.
- Hartley JL, Temple GF, Brasch MA (2001). “DNA cloning using in vitro site-specific recombination”. Genome Res. 10 (11): 1788โ95. doi:10.1101/gr.143000. PMCย 310948. PMIDย 11076863.
