Chong S S, Kozak C A, Liu L, Kristjansson K, Dunn S T, Bourdeau J E, Hughes M R
National Center for Human Genome Research, National Institutes of Health, Bethesda, Maryland 20892, USA.
Am J Physiol. 1995 Jun;268(6 Pt 2):F1038-45. doi: 10.1152/ajprenal.1995.268.6.F1038.
Renal tubular reabsorption of phosphate is critical to the maintenance of phosphate homeostasis in mammals, and the brush-border membrane Na-P(i) cotransport systems in proximal tubules play a major role in this process. We have isolated a cDNA encoding a mouse sodium-dependent phosphate transport protein (Npt1), which is expressed primarily in the kidney. This protein is highly similar to its human and rabbit homologues, based on nucleotide and amino acid comparisons. The presence of potential Asn-linked glycosylation and protein kinase C phosphorylation sites that are conserved among all three homologues suggests that these sites may be important in the function and regulation of this protein. The Npt1 gene was mapped to mouse chromosome 13, close to the Tcrg locus. By both in situ hybridization and reverse transcription-polymerase chain reaction, Npt1 mRNA was localized predominantly to the proximal tubule.
肾小管对磷酸盐的重吸收对于维持哺乳动物体内磷酸盐稳态至关重要，近端小管刷状缘膜上的钠-磷酸盐共转运系统在此过程中起主要作用。我们分离出了一个编码小鼠钠依赖性磷酸盐转运蛋白（Npt1）的cDNA，该蛋白主要在肾脏中表达。基于核苷酸和氨基酸比较，该蛋白与其人类和兔的同源物高度相似。所有三种同源物中均存在保守的潜在天冬酰胺连接的糖基化和蛋白激酶C磷酸化位点，这表明这些位点可能对该蛋白的功能和调节很重要。Npt1基因定位于小鼠13号染色体，靠近Tcrg基因座。通过原位杂交和逆转录-聚合酶链反应，Npt1 mRNA主要定位于近端小管。
