title: A novel RGD-toxin protein, Lj-RGD3, from the buccal gland secretion of Lampetra japonica impacts diverse biological activities.
abstract: RGD (Arg-Gly-Asp) motif toxin proteins from snake venoms, saliva glands secretion of leech or tick have typical characteristics of inhibiting platelet aggregation, angiogenesis, and tumor growth. Here we report cloning and characterization of a novel RGD-toxin protein from the buccal gland of Lampetra japonica. In an attempt to study the activities of anticoagulant in the buccal gland secretion of L. japonica, we established buccal gland cDNA library and identified a gene encoding a predicted protein of 118 amino acids with 3 RGD motifs. The predicted protein was named Lj-RGD3. We generated the cDNA of Lj-RGD3 and obtained the recombinant protein rLj-RGD3. The polyclonal antibodies against rLj-RGD3 recognized the native Lj-RGD3 protein in buccal gland secretion in Western blot analyses. The biological function studies reveal that rLj-RGD3 inhibited human platelet aggregation in a dose-dependent manner with IC(50) value at 5.277 μM. In addition, rLj-RGD3 repressed bFGF-induced angiogenesis in the chick chorioallantoic membrane model. rLj-RGD3 also inhibited the adhesion of ECV304 cells to vitronectin. Furthermore, rLj-RGD3 induced apoptosis and significantly inhibited proliferation, migration, and invasion evoked by bFGF in ECV304 cells. Taken together, these results suggested that rLj-RGD3 is a novel RGD-toxin protein possessing typical functions of the RGD-toxin protein.
authors.affiliation: Department of Biological Sciences, Liaoning Normal University, Dalian 116029, China.
authors.forename: Jihong
authors.initials: J
authors.lastname: Wang
authors.forename: Xiaoxi
authors.initials: X
authors.lastname: Han
authors.forename: Hsinshen
authors.initials: H
authors.lastname: Yang
authors.forename: Li
authors.initials: L
authors.lastname: Lu
authors.forename: Yu
authors.initials: Y
authors.lastname: Wu
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Renyong
authors.initials: R
authors.lastname: Guo
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yaqian
authors.initials: Y
authors.lastname: Zhang
authors.forename: Qingwei
authors.initials: Q
authors.lastname: Li
mesh_terms: D020816:Amino Acid Motifs; D020533:Angiogenesis Inhibitors; D000818:Animals; D000925:Anticoagulants; D000970:Antineoplastic Agents; D002478:Cells, Cultured; D002610:Cheek; D002642:Chick Embryo; D018076:DNA, Complementary; D005397:Fish Venoms / Q000032:analysis / Q000737:chemistry* / Q000494:pharmacology*; D015723:Gene Library; D006801:Humans; D007798:Lampreys; D009842:Oligopeptides / Q000032:analysis*; D010975:Platelet Aggregation Inhibitors
chemical_list: D020533:Angiogenesis Inhibitors; D000925:Anticoagulants; D000970:Antineoplastic Agents; D018076:DNA, Complementary; D005397:Fish Venoms; D009842:Oligopeptides; D010975:Platelet Aggregation Inhibitors; C047981:arginyl-glycyl-aspartic acid