title: The human apolipoprotein L gene cluster: identification, classification, and sites of distribution.
abstract: We report the cloning of a new gene family encoding six apolipoprotein L (apoL-I to -VI) proteins. The genes were identified as a cluster spanning a region of 619 kb on chromosome 22. Each apoL was found to share significant identity in its predicted amphipathic alpha helices while phylogenetic tree mapping showed the genes to be evolutionarily conserved. Tissue distribution by semiquantitative PCR revealed expression in all tissues, but consistently higher levels in the placenta were observed, except for apoL-V, which had a restricted expression. A comparison of tissue distribution with apoA-I, the major structural component of high-density lipoprotein, suggests that the apoL proteins may play a general and fundamental role in lipid biochemistry. In situ hybridization for expression of apoL-I in the placenta revealed expression throughout this tissue. The pathological expression of the apolipoproteins during pregnancy is implicated in fetal growth retardation, preeclampsia, and the onset of adult atherosclerosis.
authors.affiliation: School of Animal and Microbial Sciences, The University of Reading, Reading, RG6 6AJ, United Kingdom. sasnpagereading.ac.uk
authors.forename: N M
authors.initials: NM
authors.lastname: Page
authors.forename: D J
authors.initials: DJ
authors.lastname: Butlin
authors.forename: K
authors.initials: K
authors.lastname: Lomthaisong
authors.forename: P J
authors.initials: PJ
authors.lastname: Lowry
mesh_terms: D000595:Amino Acid Sequence; D000075944:Apolipoprotein L1; D001053:Apolipoproteins / Q000235:genetics*; D002874:Chromosome Mapping; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D019143:Evolution, Molecular; D005091:Exons; D005260:Female; D015870:Gene Expression; D023061:Gene Order; D005796:Genes / Q000235:genetics; D006801:Humans; D007438:Introns; D008075:Lipoproteins, HDL / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution
chemical_list: C108666:APOL1 protein, human; D000075944:Apolipoprotein L1; D001053:Apolipoproteins; D018076:DNA, Complementary; D008075:Lipoproteins, HDL; D012333:RNA, Messenger