Extended Synaptotagmin Interaction with the Fibroblast Growth Factor Receptor Depends on Receptor Conformation, Not Catalytic Activity.
We previously demonstrated that ESyt2 interacts specifically with the activated FGF receptor and is required for a rapid phase of receptor internalization and for functional signaling via the ERK pathway in early Xenopus embryos. ESyt2 is one of the three-member family of Extended Synaptotagmins that were recently shown to be implicated in the formation of endoplasmic reticulum (ER)-plasma membrane (PM) junctions and in the Ca(2+) dependent regulation of these junctions. Here we show that ESyt2 is directed to the ER by its putative transmembrane domain, that the ESyts hetero- and homodimerize, and that ESyt2 homodimerization in vivo requires a TM adjacent sequence but not the SMP domain. ESyt2 and ESyt3, but not ESyt1, selectively interact in vivo with activated FGFR1. In the case of ESyt2, this interaction requires a short TM adjacent sequence and is independent of receptor autophosphorylation, but dependent on receptor conformation. The data show that ESyt2 recognizes a site in the upper kinase lobe of FGFR1 that is revealed by displacement of the kinase domain activation loop during receptor activation.
From the Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Québec University Hospital Research Centre, and Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Edifice St Patrick, 9 rue McMahon, Québec, Québec G1R 3S3, Canada.
Michel G
MG
Tremblay
From the Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Québec University Hospital Research Centre, and Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Edifice St Patrick, 9 rue McMahon, Québec, Québec G1R 3S3, Canada.
Chelsea
C
Herdman
From the Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Québec University Hospital Research Centre, and Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Edifice St Patrick, 9 rue McMahon, Québec, Québec G1R 3S3, Canada.
François
F
Guillou
From the Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Québec University Hospital Research Centre, and Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Edifice St Patrick, 9 rue McMahon, Québec, Québec G1R 3S3, Canada.
Prakash K
PK
Mishra
From the Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Québec University Hospital Research Centre, and Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Edifice St Patrick, 9 rue McMahon, Québec, Québec G1R 3S3, Canada.
Joëlle
J
Baril
From the Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Québec University Hospital Research Centre, and Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Edifice St Patrick, 9 rue McMahon, Québec, Québec G1R 3S3, Canada.
Sabrina
S
Bellenfant
From the Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Québec University Hospital Research Centre, and Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Edifice St Patrick, 9 rue McMahon, Québec, Québec G1R 3S3, Canada Tom.Moss@crhdq.ulaval.ca.
Tom
http://orcid.org/0000-0003-2047-4783
T
Moss
D000595:Amino Acid Sequence; D020134:Catalytic Domain; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D051496:Receptor, Fibroblast Growth Factor, Type 1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D050857:Synaptotagmins / Q000235:genetics / Q000378:metabolism*
C583132:ESYT1 protein, human; C573315:ESYT2 protein, human; C571229:ESYT3 protein, human; D050857:Synaptotagmins; D051496:Receptor, Fibroblast Growth Factor, Type 1
ESyt-FGFR complex; Extended-Synaptotagmin (ESyt1, 2, 3); FGFR activity; FGFR conformation; dimerization; fibroblast growth factor receptor (FGFR); receptor endocytosis; receptor modification; receptor structure-function; receptor tyrosine kinase