Identification of pleckstrin-homology-domain-containing proteins with novel phosphoinositide-binding specificities
Identification of pleckstrin-homology-domain-containing proteins with novel phosphoinositide-binding specificities
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DOI：
10.1042/0264-6021:3510019
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发表时间：
2000-10-01
影响因子：
4.1
通讯作者：
Alessi, DR
中科院分区：
文献类型：
--
作者：
Dowler, S;Currie, RA;Alessi, DR
第二信使磷脂酰肌醇 3,4,5-三磷酸 [PtdIns(3,4,5)P-3] 由磷酸肌醇 3-激酶 (PI 3-激酶) 的作用产生，并调节大量的细胞过程。剖析这些过程调节机制的一种方法是鉴定与 PtdIns(3,4,5)P-3 特异性相互作用的蛋白质。 pleckstrin 同源 (PH) 结构域已被认为是许多蛋白质用来与 PtdIns(3,4,5)P-3 相互作用的专门模块。最近的工作导致在与该脂质相互作用的 PH 结构域的 N 末端区域鉴定出假定的磷脂酰肌醇 3,4,5-三磷酸结合基序 (PPBM)。我们在表达序列标签数据库中搜索了包含具有 PPBM 的 PH 结构域的新型蛋白质。令人惊讶的是，我们鉴定的许多 PH 结构域不结合 PtdIns(3,4,5)P-3，而是在体外具有意想不到的新型磷酸肌醇结合特异性。这些包括具有与 PtdIns(3,4)P-2 [TAPP1（包含串联 PH 结构域的蛋白-1）和 TAPP2]、Ptd-Ins4P [FAPP1（磷脂酰肌醇四磷酸衔接蛋白-1）]、PtdIns3P [PEPP1（磷脂酰肌醇三磷酸结合 PH 结构域蛋白-1）和 AtPH1] 特异性相互作用的 PH 结构域的蛋白质和 PtdIns(3,5)P-2（半人马座蛋白-β 2）。我们还鉴定了 PEPP1 的两个相关同源物，称为 PEPP2 和 PEPP3，它们也可能与 PtdIns3P 相互作用。这项研究为未来确定这些蛋白质在体内的磷脂结合特异性及其生理作用奠定了基础。
The second messenger phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P-3] is generated by the action of phosphoinositide 3-kinase (PI 3-kinase), and regulates a plethora of cellular processes. An approach for dissecting the mechanisms by which these processes are regulated is to identify proteins that interact specifically with PtdIns(3,4,5)P-3. The pleckstrin homology (PH) domain has become recognized as the specialized module used by many proteins to interact with PtdIns(3,4,5)P-3. Recent work has led to the identification of a putative phosphatidylinositol 3,4,5-trisphosphate-binding motif (PPBM) at the N-terminal regions of PH domains that interact with this lipid. We have searched expressed sequence tag databases for novel proteins containing PH domains possessing a PPBM. Surprisingly, many of the PH domains that we identified do not bind PtdIns(3,4,5)P-3, but instead possess unexpected and novel phosphoinositide-binding specificities in vitro. These include proteins possessing PH domains that interact specifically with PtdIns(3,4)P-2 [TAPP1 (tandem PH-domain-containing protein-1) and TAPP2], Ptd-Ins4P [FAPP1 (phosphatidylinositol-four-phosphate adaptor protein-1)], PtdIns3P [PEPP1 (phosphatidylinositol-three-phosphate-binding PH-domain protein-1) and AtPH1] and PtdIns(3,5)P-2 (centaurin-beta 2). We have also identified two related homologues of PEPP1, termed PEPP2 and PEPP3, that may also interact with PtdIns3P. This study lays the foundation for future work to establish the phospholipid-binding specificities of these proteins in vivo, and their physiological role(s).