apoa4 apoa4 apolipoprotein a-iv (also known as apoa-iv, apoaiv, or apoa4) is plasma protein that is the product of the human gene apoa4. apoa4identifiersaliasesapoa4, apolipoprotein a4external idsomim: 107690 mgi: 88051 homologene: 47927 genecards: apoa4 gene location (human)chr.chromosome 11 (human)band11q23.3start116,820,700 bpend116,823,304 bpgene location (mouse)chr.chromosome 9 (mouse)band9 a5.2|9 25.36 cmstart46,151,994 bpend46,154,757 bprna expression patternbgeehumanmouse (ortholog)top expressed injejunal mucosaduodenumright lobe of livervena cavainternal globus palliduspericardiumponspylorussaphenous veinsuperior vestibular nucleustop expressed induodenumjejunumyolk sacileumcumulus cellintestinal epitheliumleft lobe of liverstomachintestinal villusepithelium of stomachmore reference expression databiogpsmore reference expression dataorthologsspecieshumanmouseentrez33711808ensemblensg00000110244ensmusg00000032080uniprotnap06728refseq (mrna)nm_000482nm_007468refseq (protein)n/anp_031494location (ucsc)chr 11: 116.82 – 116.82 mbchr 9: 46.15 – 46.15 mbpubmed searchwikidataview/edit humanview/edit mouse gene apoa4 resides on chromosome 11 in close linkage to apoa1 and apoc3. apoa4 contains 3 exons separated by two introns, and is polymorphic, although most of the reported sequence polymorphisms occur in exon 3. the best validated and studied non-synonymous snps are a glutamine → histidine substitution at codon 360 and a threonine → serine substitution at codon 347; a sequence polymorphism has also been identified in the 3'utr of the third exon. intra-species comparative gene sequence analysis suggests that the apoa4 gene arose from apoa1 by gene duplication approximately 270 mya. function the primary translation product of the apoa4 gene is a 396-residue preprotein, which undergoes proteolytic processing to yield apo a-iv, a 376-residue mature o-linked glycoprotein. in most mammals, including humans, apo a-iv synthesis is confined to the intestine; however in mice and rats hepatic synthesis also occurs. apo a-iv is secreted into circulation on the surface of newly synthesized chylomicron particles. intestinal fat absorption dramatically increases the synthesis and secretion of apo a-iv. although its primary function in human lipid metabolism has not been established, apo a-iv has been found to: activate lecithin-cholesterol acyltransferase and cholesterylester transfer protein in vitro; play a role in the regulation of appetite and satiety in rodent models; display anti-oxidant and anti-atherogenic properties in vitro and in rodent models; modulate the efficiency of enterocyte and hepatic transcellular lipid transport in vitro. human apo a-iv deficiency has not been reported. interactions apoa4 has been shown to interact with gpld1. interactive pathway map click on genes, proteins and metabolites below to link to respective articles. [[file: |alt=statin pathway edit]] statin pathway edit the interactive pathway map can be edited at wikipathways: "statin_pathway_wp430".