title: GK4, a G-protein-coupled receptor with a phosphatidylinositol phosphate kinase domain in Phytophthora infestans, is involved in sporangia development and virulence.
abstract: For dispersal and host infection plant pathogens largely depend on asexual spores. Pathogenesis and sporulation are complex processes that are governed by cellular signalling networks including G-protein and phospholipid signalling. Oomycetes possess a family of novel proteins called GPCR-PIPKs (GKs) that are composed of a seven-transmembrane spanning (7-TM) domain fused to a phosphatidylinositol phosphate kinase (PIPK) domain. Based on this domain structure GKs are anticipated to link G-protein and phospholipid signal pathways; however, their functions are currently unknown. Expression analyses of the 12 GK genes in Phytophthora infestans and their orthologues in Phytophthora sojae, revealed differential expression during asexual development. PiGK1 and PiGK4 were fused to monomeric red fluorescent protein (mRFP) and ectopically expressed in P. infestans. In growing hyphae different subcellular distribution patterns were observed indicating that these two GKs act independently during development. We focused on the functional analyses of PiGK4. Its localization suggested involvement in cell differentiation and elongation and its 7-TM domain showed a canonical GPCR membrane topology. Silencing of GK4 and overexpression of full-length and truncated constructs in P. infestans revealed that PiGK4 is not only involved in spore germination and hyphal elongation but also in sporangia cleavage and infection.
authors: Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
authors: Chenlei
authors: C
authors: Hua
authors: Harold J G
authors: HJ
authors: Meijer
authors: Jeroen
authors: J
authors: de Keijzer
authors: Wei
authors: W
authors: Zhao
authors: Yuanchao
authors: Y
authors: Wang
authors: Francine
authors: F
authors: Govers
mesh_terms: D018507:Gene Expression Regulation, Developmental; D025301:Hyphae / Q000254:growth & development; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism*; D010770:Phosphotransferases / Q000235:genetics / Q000378:metabolism*; D055750:Phytophthora infestans / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism / Q000472:pathogenicity*; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D043562:Receptors, G-Protein-Coupled / Q000737:chemistry* / Q000378:metabolism; D011198:Solanum tuberosum / Q000382:microbiology; D058432:Sporangia / Q000254:growth & development*; D013170:Spores / Q000254:growth & development; D014026:Nicotiana / Q000382:microbiology; D000097573:Red Fluorescent Protein
chemical_list: D008164:Luminescent Proteins; D018129:Phosphatidylinositol Phosphates; D010770:Phosphotransferases; D043562:Receptors, G-Protein-Coupled; D000097573:Red Fluorescent Protein