Magyar A, Váradi A
Institute of Enzymology, Hungarian Academy of Sciences, Budapest.
Biochem Biophys Res Commun. 1990 Dec 31;173(3):872-7. doi: 10.1016/s0006-291x(05)80867-8.
We report here the characterization of a Drosophila melanogaster cDNA that encodes a sarco/endoplasmic reticulum-type Ca2(+)-ATPase. Previously we amplified the phosphorylation site - FITC-binding site fragment of this cDNA by Polymerase Chain Reaction utilizing homology primers (Váradi, A., Gilmore-Hebert, M. and Benz, E. J. Jr. (1989) FEBS Letters 258 203-207) and in the present work we used this fragment as probe for isolation of a cDNA clone with the intire coding region. The isolated 3.3 kb clone has been sequenced and the primary structure of the encoded protein has been deduced. It consists of 1002 amino acids with all the characteristic features of the P-type ATPases. It shows 67-71% amino acid identity and an apparently identical hydropathy profile with the mammalian sarco/endoplasmic reticulum-type Ca2(+)-ATPases. On basis of sequence similarity we suggest that the first transmembrane segment of sarco/endoplasmic reticulum type Ca2(+)-ATPases may be responsible for targeting of these transport proteins into the organellar membrane. The gene of this sarco/endoplasmic reticulum-type Ca2(+)-ATPase has been mapped on the right arm of chromosome 2, in section 60A.
我们在此报告了一个编码肌浆网/内质网型Ca2+ -ATP酶的黑腹果蝇cDNA的特征。此前我们利用同源引物通过聚合酶链反应扩增了该cDNA的磷酸化位点 - 异硫氰酸荧光素结合位点片段（瓦拉迪，A.，吉尔摩 - 赫伯特，M.和本兹，E. J. Jr.（1989年）《欧洲生物化学学会联合会快报》258 203 - 207），在本研究中我们用该片段作为探针来分离具有完整编码区的cDNA克隆。分离得到的3.3 kb克隆已进行测序，并推导了所编码蛋白质的一级结构。它由1002个氨基酸组成，具有P型ATP酶的所有特征。它与哺乳动物肌浆网/内质网型Ca2+ -ATP酶显示出67 - 71%的氨基酸同一性以及明显相同的亲水性图谱。基于序列相似性，我们认为肌浆网/内质网型Ca2+ -ATP酶的第一个跨膜区段可能负责将这些转运蛋白靶向到细胞器膜上。这种肌浆网/内质网型Ca2+ -ATP酶的基因已定位在2号染色体右臂的60A区段。
