4rj9
From Proteopedia
Structure of a plant specific C2 domain protein, OsGAP1 from rice
Structural highlights
FunctionGAP1_ORYSJ Mediates the transient calcium-dependent interaction of PYR/PYL/RCAR abscisic acid (ABA) receptors with the plasma membrane and thus regulates ABA sensitivity (By similarity). Stimulates the GTPase/ATPase activities of YchF1, and regulates its subcellular localization. Promotes tolerance towards salinity stress by limiting the accumulation of reactive oxygen species (ROS) (PubMed:19086295, PubMed:23550829). Promotes resistance to bacterial pathogens (e.g. Xanthomonas oryzae pv. oryzae and P. syringae pv. tomato DC3000) (PubMed:19086295).[UniProtKB:Q9LVH4][1] [2] Publication Abstract from PubMedThe C2 domain is one of the most diverse phospholipid-binding domains mediating cellular signaling. One group of C2-domain proteins are plant-specific and are characterized by their small sizes and simple structures. We have previously reported that a member of this group, OsGAP1, is able to alleviate salt stress and stimulate defense responses, and bind to both phospholipids and an unconventional G-protein, OsYchF1. Here we solved the crystal structure of OsGAP1 to a resolution of 1.63 A. Using site-directed mutagenesis, we successfully differentiated between the clusters of surface residues that are required for binding to phospholipids versus OsYchF1, which, in turn, is critical for its role in stimulating defense responses. On the other hand, the ability to alleviate salt stress by OsGAP1 is dependent only on its ability to bind OsYchF1 and is independent of its phospholipid-binding activity. Site-Directed Mutagenesis Shows the Significance of Interactions with Phospholipids and the G-protein OsYchF1 on the Physiological Functions of the Rice GTPase-Activating Protein 1 (OsGAP1).,Yung YL, Cheung MY, Miao R, Fong YH, Li KP, Yu MH, Chye ML, Wong KB, Lam HM J Biol Chem. 2015 Aug 18. pii: jbc.M115.655639. PMID:26286751[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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