The family of phospholipase C (PLC) isoforms can be divided into three classes β, γ, and δ. Song et al. have identified a fourth class of PLC, PLCε, which has sequence similarity to the Caenorhabditis elegans PLC210, including two putative Ras-interacting domains (CDC25-like domain and an RA domain). However, it lacks the conserved pleckstrin homology domain and EF-hand domains of all other classes of PLC. Analysis of recombinant PLCε showed that the protein has phospholipase C activity with a dependence on calcium similar to that of other PLC isoforms. PLCε interacted with the guanosine triphosphatases Ras and Rap1, and this interaction led to the recruitment of PLCε to the plasma membrane or the perinuclear region, respectively, in cells transfected with a green fluorescent protein (GFP)-tagged PLCε and activated forms of Ras or Rap1. Furthermore, the translocation of PLCε to membranes was stimulated in cells treated with epidermal growth factor, and this effect was blocked by expression of dominant negative Ras, supporting the model that Ras recruits the PLCε to the membrane in response to external stimuli.
C. Song, C.-D. Hu, M. Misago, K.-i. Kariya, Y. Yamawaki-Kataoka, M. Shibatohge, D. Wu, T. Satoh, T. Katoaka, Regulation of a novel human phospholipase C, PLCε, through membrane targeting by Ras. J. Biol. Chem. 276, 2752-2757 (2001). [Abstract] [Full Text]