Janssens R, Boeynaems J M, Godart M, Communi D
Institute of Interdisciplinary Research, School of Medicine, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium.
Biochem Biophys Res Commun. 1997 Jul 9;236(1):106-12. doi: 10.1006/bbrc.1997.6895.
The 6H1 receptor cloned from activated chicken T cells was initially considered an orphan G-coupled receptor, but was later included in the P2Y family of receptors for purine and pyrimidine nucleotides on the basis of a significant amino acid identity and was renamed P2Y5. Analysis of the expressed sequence tag database revealed the presence of a related sequence exhibiting 63% amino acid identity with this receptor. Starting from this partial sequence, we have isolated a complete clone and identified a 1113 base pair open reading frame encoding a new G-coupled receptor that we have called P2Y5-like. This sequence exhibits 61% identity with the chicken P2Y5 sequence and 30-33% with other P2Y subtypes. A construct encoding this P2Y5-like receptor was transfected into COS-7, 1321N1, and CHO-K1 cells, and expression was documented by Northern blotting. None of the 40 nucleotides and nucleosides tested was able to elicit a response in any of four functional assays: inositol phosphate formation, stimulation or inhibition of cAMP formation, and extracellular acidification measured with a microphysiometer. These results suggest either that the natural ligand of the P2Y5-like receptor is an uncommon nucleotide or alternatively that despite its structural similarity to the P2Y family it is not a nucleotide receptor.
从活化的鸡T细胞中克隆出的6H1受体最初被认为是一种孤儿G偶联受体，但后来基于显著的氨基酸同源性被归入嘌呤和嘧啶核苷酸的P2Y受体家族，并被重新命名为P2Y5。对表达序列标签数据库的分析显示存在一个与该受体具有63%氨基酸同源性的相关序列。从这个部分序列开始，我们分离出了一个完整的克隆，并鉴定出一个1113个碱基对的开放阅读框，其编码一种新的G偶联受体，我们将其称为P2Y5样受体。该序列与鸡P2Y5序列具有61%的同源性，与其他P2Y亚型具有30 - 33%的同源性。将编码这种P2Y5样受体的构建体转染到COS - 7、1321N1和CHO - K1细胞中，并通过Northern印迹法证明了其表达。在所测试的40种核苷酸和核苷中，没有一种能够在四种功能测定中的任何一种中引发反应：肌醇磷酸形成、cAMP形成的刺激或抑制以及用微生理计测量的细胞外酸化。这些结果表明，要么P2Y5样受体的天然配体是一种不常见的核苷酸，要么尽管它与P2Y家族在结构上相似，但它不是一种核苷酸受体。
