Mikami Koji, Repp Alexander, Graebe-Abts Elena, Hartmann Elmar
National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan.
J Exp Bot. 2004 Jun;55(401):1437-9. doi: 10.1093/jxb/erh140. Epub 2004 Apr 8.
Two cDNAs encoding proteins, PpPLC1 and PpPLC2, with catalytic and C2 domains conserved in plant phosphoinositide-specific phospholipase C (PI-PLC) were isolated from Physcomitrella patens. The N domain, which has been identified in Arabidopsis PI-PLCs as an EF hand-like domain, was found in both isoforms, although that in PpPLC2 was a split type. At micromolar Ca2+ concentrations, PpPLC1 preferentially hydrolysed phosphatidylinositol-4,5-bisphosphate, while PpPLC2 showed no specificity. Furthermore, at millimolar Ca2+, phosphatidylinositol was hydrolysed by PpPLC2, but not by PpPLC1. Thus, PpPLC1 and PpPLC2 are typical and novel types of plant PI-PLC, respectively.
从小立碗藓中分离出了两个编码蛋白质PpPLC1和PpPLC2的cDNA，它们具有在植物磷脂酰肌醇特异性磷脂酶C（PI-PLC）中保守的催化结构域和C2结构域。在这两种异构体中都发现了在拟南芥PI-PLC中被鉴定为EF手样结构域的N结构域，尽管PpPLC2中的N结构域是分裂型的。在微摩尔浓度的Ca2+下，PpPLC1优先水解磷脂酰肌醇-4,5-二磷酸，而PpPLC2没有特异性。此外，在毫摩尔浓度的Ca2+下，PpPLC2可水解磷脂酰肌醇，而PpPLC1则不能。因此，PpPLC1和PpPLC2分别是典型的和新型的植物PI-PLC。
