Human aquaporin adipose (AQPap) gene. Genomic structure, promoter analysis and functional mutation.
Aquaporin adipose (AQPap), which we identified from human adipose tissue, is a glycerol channel in adipocyte [Kishida et al. (2000) J. Biol. Chem. 275, 20896-20902]. In the current study, we determined the genomic structure of the human AQPap gene, and identified three AQPap-like genes that resembled (approximately 95%) AQPap, with little expression in human tissues. The AQPap promoter contained a putative peroxisome proliferator response element (PPRE) at -46 to -62, and a putative insulin response element (IRE) at -542/-536. Deletion of the PPRE abolished the pioglitazone-mediated induction of AQPap promoter activity in 3T3-L1 adipocytes. Deletion and single base pair substitution analysis of the IRE abolished the insulin-mediated suppression of the human AQPap gene. Analysis of AQPap sequence in human subjects revealed three missense mutations (R12C, V59L and G264V), and two silent mutations (A103A and G250G). The cRNA injection of the missense mutants into Xenopus oocytes revealed the absence of the activity to transport glycerol and water in the AQPap-G264V protein. In the subject homozygous for AQPap-G264V, exercise-induced increase in plasma glycerol was not observed in spite of the increased plasma noradrenaline. We suggest that AQPap is responsible for the increase of plasma glycerol during exercise in humans.
Kondo
Hidehiko
H
Department of Internal Medicine and Molecular Science, Graduate School of Medicine, Osaka University, Yamadaoka, Suita, Japan.
Shimomura
Iichiro
I
Kishida
Ken
K
Kuriyama
Hiroshi
H
Makino
Yasunaka
Y
Nishizawa
Hitoshi
H
Matsuda
Morihiro
M
Maeda
Norikazu
N
Nagaretani
Hiroyuki
H
Kihara
Shinji
S
Kurachi
Yoshihisa
Y
Nakamura
Tadashi
T
Funahashi
Tohru
T
Matsuzawa
Yuji
Y
D020346:Aquaporins / Q000235:genetics*; D001483:Base Sequence; D015139:Blotting, Southern; D015153:Blotting, Western; D002874:Chromosome Mapping; D002899:Chromosomes, Human, Pair 9; D017931:DNA Primers; D005091:Exons; D006801:Humans; D006822:Hybrid Cells / Q000528:radiation effects; D007438:Introns; D009154:Mutation; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction
C114141:AQP7 protein, human; D020346:Aquaporins; D017931:DNA Primers