Apolipoprotein A-II (APOA2)
The protein contains 100 amino acids for an estimated molecular weight of 11175 Da.
May stabilize HDL (high density lipoprotein) structure by its association with lipids, and affect the HDL metabolism. (updated: Sept. 12, 2018)
Protein identification was indicated in the following studies:
Methods
The following articles were analysed to gather the proteome content of erythrocytes.
The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry
The compilation of older studies can be retrieved from the Red Blood Cell Collection database.
The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.
No sequence conservation computed yet.
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Biological Process
Acute inflammatory response
Animal organ regeneration
Cellular protein metabolic process
Cholesterol efflux
Cholesterol homeostasis
Cholesterol metabolic process
Cholesterol transport
Chylomicron assembly
Chylomicron remodeling
Diacylglycerol catabolic process
High-density lipoprotein particle assembly
High-density lipoprotein particle clearance
High-density lipoprotein particle remodeling
Intermembrane lipid transfer
Lipoprotein metabolic process
Low-density lipoprotein particle remodeling
Negative regulation of cholesterol import
Negative regulation of cholesterol transport
Negative regulation of cholesterol transporter activity
Negative regulation of cytokine production involved in immune response
Negative regulation of cytokine secretion involved in immune response
Negative regulation of lipase activity
Negative regulation of lipid catabolic process
Negative regulation of very-low-density lipoprotein particle remodeling
Peptidyl-methionine modification
Phosphatidylcholine biosynthetic process
Phospholipid catabolic process
Phospholipid efflux
Positive regulation of cholesterol esterification
Positive regulation of interleukin-8 biosynthetic process
Positive regulation of interleukin-8 production
Positive regulation of lipid catabolic process
Positive regulation of phagocytosis
Post-translational protein modification
Protein oxidation
Protein stabilization
Regulation of intestinal cholesterol absorption
Regulation of lipid metabolic process
Regulation of metabolic process
Regulation of protein stability
Response to drug
Response to estrogen
Response to glucocorticoid
Response to glucose
Retinoid metabolic process
Reverse cholesterol transport
Triglyceride metabolic process
Triglyceride-rich lipoprotein particle remodeling
Viral process
Cellular Component
Blood microparticle
Chylomicron
Cytosol
Early endosome
Endoplasmic reticulum lumen
Extracellular exosome
Extracellular region
High-density lipoprotein particle
Spherical high-density lipoprotein particle
Very-low-density lipoprotein particle
Molecular Function
Apolipoprotein receptor binding
Cholesterol binding
Cholesterol transfer activity
Cholesterol transporter activity
Heat shock protein binding
High-density lipoprotein particle binding
High-density lipoprotein particle receptor binding
Lipase inhibitor activity
Lipid binding
Lipid transporter activity
Phosphatidylcholine binding
Phosphatidylcholine-sterol O-acyltransferase activator activity
Phospholipid binding
Protein heterodimerization activity
Protein homodimerization activity
Signaling receptor binding
The reference OMIM entry for this protein is 107670
Apolipoprotein a-ii; apoa2 apolipoprotein a-ii deficiency, included
DESCRIPTION
Apolipoprotein A-II, like apolipoprotein A-I (APOA1; 107680), is a major apolipoprotein in high density lipoprotein (HDL).CLONING
Sakaguchi et al. (1984) and Lackner et al. (1984) isolated the gene for apolipoprotein A-II from a human cDNA library using synthetic oligonucleotides as probes.MAPPING
Sakaguchi et al. (1984) and Lackner et al. (1984) isolated a restriction fragment of 300 bp from an apoA-II cDNA clone and used it as a probe in filter hybridization assay of DNA from human-mouse somatic cell hybrids. Restriction digestion was performed with HindIII. They found that apoA-II segregates with chromosome 1. The gene was regionalized to 1p21-qter and may reside in a conserved linkage group with renin and peptidase C. Moore et al. (1984) confirmed the assignment of the APOA2 gene to chromosome 1. By in situ hybridization, Middleton-Price et al. (1988) mapped the APOA2 gene to 1q21-q23. Southern hybridization to the DNA from somatic cell hybrids made from cells carrying a balanced translocation between X and 1 confirmed the localization as proximal to 1q23. In the course of creating a physical map of human 1q21-q23, Oakey et al. (1992) confirmed this assignment. Using a cDNA probe, Rogne et al. (1989) found tight linkage with Duffy blood group (FY; 110700). No recombination was found in 19 meioses examined, giving a maximal lod score of 4.2 at theta = 0.0. This information, combined with other data, made the most likely distance between FY and APOA2 about 10% recombination, with a combined lod score of 5.6 for both sexes. In the mouse, the genes for apoA-I and apoA-II are on separate chromosomes (Lusis et al., 1983)--mouse chromosomes 9 and 1, respectively. Thus, in man, apoA-II was presumably not coded by 11q, the site of the APOA1 gene.GENE FUNCTION
Apolipoprotein A-II is the second most abundant protein of high density lipoprotein particles. Warden et al. (1993) showed that in both mice and humans, the APOA2 gene is linked to a gene that controls plasma levels of apoA-II and that the APOA2 gene or its product influences, by an unknown mechanism, plasma levels of free fatty acids (FFA). Allayee et al. (2003) studied 18 extended families of Dutch Caucasian descent with familial combined hyperlipidemia (FCHL; 144250) and found that, despite having lower levels of HDLC, FCHL subjects had higher apoA-II levels compared with unaffected relatives (p less than 0.00016). Triglyceride and HDL-C levels were significant predictors of apoA-II levels, demonstrating that apoA-II variation is associated with several FCHL-related traits. After adjustment for multiple covariates, there was evidence for the heritability of apoA-II levels (h-squared = 0.15; p less than 0.02) in this sample. A genome scan for apoA-II levels identified significant evidence (lod = 3.1) for linkage to a locus on chromosome 1q41, coincident with a suggestive linkage for triglycerides (lod = 1.4), suggesting that this locus may have pleiotropic effects on apoA-II and FCHL traits. Allayee et al. (2003) concluded that apoA-II is biochemically and genetically associated with FCHL and may serve as a useful marker for understanding the mechanism by which FCHL develops.MOLECULAR GENETICS
Kessling et al. (1988) studied the high density lipoprotein-cholesterol concentrations (HDLC) along with RFLPs in the APOA2 and APOA1-APOC3-APOA4 gene cluster in 109 men selected from a random sample of 1,910 men aged 45 to 5 ... More on the omim web site
Subscribe to this protein entry history 
Oct. 19, 2018: Protein entry updated
Automatic update: OMIM entry 107670 was added.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).