title: The direct interaction of phospholipase C-gamma 1 with phospholipase D2 is important for epidermal growth factor signaling.
abstract: The epidermal growth factor (EGF) receptor has an important role in cellular proliferation, and the enzymatic activity of phospholipase C (PLC)-gamma1 is regarded to be critical for EGF-induced mitogenesis. In this study, we report for the first time a phospholipase complex composed of PLC-gamma1 and phospholipase D2 (PLD2). PLC-gamma1 is co-immunoprecipitated with PLD2 in COS-7 cells. The results of in vitro binding analysis and co-immunoprecipitation analysis in COS-7 cells show that the Src homology (SH) 3 domain of PLC-gamma1 binds to the proline-rich motif within the Phox homology (PX) domain of PLD2. The interaction between PLC-gamma1 and PLD2 is EGF stimulation-dependent and potentiates EGF-induced inositol 1,4,5-trisphosphate (IP(3)) formation and Ca(2+) increase. Mutating Pro-145 and Pro-148 within the PX domain of PLD2 to leucines disrupts the interaction between PLC-gamma1 and PLD2 and fails to potentiate EGF-induced IP(3) formation and Ca(2+) increase. However, neither PLD2 wild type nor PLD2 mutant affects the EGF-induced tyrosine phosphorylation of PLC-gamma1. These findings suggest that, upon EGF stimulation, PLC-gamma1 directly interacts with PLD2 and this interaction is important for PLC-gamma1 activity.
authors.affiliation: Department of Life Science and Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea.
authors.forename: Il Ho
authors.initials: IH
authors.lastname: Jang
authors.forename: Sukmook
authors.initials: S
authors.lastname: Lee
authors.forename: Jong Bae
authors.initials: JB
authors.lastname: Park
authors.forename: Jong Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Chang Sup
authors.initials: CS
authors.lastname: Lee
authors.forename: Eun-Mi
authors.initials: EM
authors.lastname: Hur
authors.forename: Il Shin
authors.initials: IS
authors.lastname: Kim
authors.forename: Kyong-Tai
authors.initials: KT
authors.lastname: Kim
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yagisawa
authors.forename: Pann-Ghill
authors.initials: PG
authors.lastname: Suh
authors.forename: Sung Ho
authors.initials: SH
authors.lastname: Ryu
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D019556:COS Cells; D002118:Calcium / Q000378:metabolism; D002455:Cell Division; D004305:Dose-Response Relationship, Drug; D004815:Epidermal Growth Factor / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D009154:Mutation; D051966:Phospholipase C gamma; D010739:Phospholipase D / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D011233:Precipitin Tests; D011392:Proline / Q000737:chemistry; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection; D010738:Type C Phospholipases / Q000737:chemistry / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism; D018909:src Homology Domains
chemical_list: D011993:Recombinant Fusion Proteins; D014443:Tyrosine; D004815:Epidermal Growth Factor; D015544:Inositol 1,4,5-Trisphosphate; D011392:Proline; D010738:Type C Phospholipases; C105606:phospholipase D2; D051966:Phospholipase C gamma; D010739:Phospholipase D; D005978:Glutathione; D002118:Calcium