title: Bm-TFF2, a trefoil factor protein with platelet activation activity from frog Bombina maxima skin secretions.
abstract: In mammals, trefoil factor family (TFF) proteins are involved in mucosal maintenance and repair, and they are also implicated in tumor suppression and cancer progression. A novel two domain TFF protein from frog Bombina maxima skin secretions (Bm-TFF2) has been purified and cloned. It activated human platelets in a dose-dependent manner and activation of integrin alpha(IIb)beta(3) was involved. Aspirin and apyrase did not largely reduce platelet response to Bm-TFF2 (a 30% inhibition), indicating that the aggregation is not substantially dependent on ADP and thromboxane A2 autocrine feedback. Elimination of external Ca(2+) with EGTA did not influence the platelet aggregation induced by Bm-TFF2, meanwhile a strong calcium signal (cytoplasmic Ca(2+) release) was detected, suggesting that activation of phospholipase C (PLC) is involved. Subsequent immunoblotting revealed that, unlike in platelets activated by stejnulxin (a glycoprotein VI agonist), PLCgamma2 was not phosphorylated in platelets activated by Bm-TFF2. FITC-labeled Bm-TFF2 bound to platelet membranes. Bm-TFF2 is the first TFF protein reported to possess human platelet activation activity.
authors.affiliation: Department of Animal Toxinology, Kunming Institute of Zoology, The Chinese Academy of Sciences, Kunming, Yunnan 650223, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shao-Gui
authors.initials: SG
authors.lastname: Wan
authors.forename: Shuang-Shuang
authors.initials: SS
authors.lastname: Wei
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Lee
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001001:Anura; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009077:Mucins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D009124:Muscle Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D015539:Platelet Activation / Q000187:drug effects*; D011485:Protein Binding; D012867:Skin / Q000378:metabolism; D000071164:Trefoil Factor-2
chemical_list: D009077:Mucins; D009124:Muscle Proteins; D010455:Peptides; C000604007:TFF2 protein, human; D000071164:Trefoil Factor-2; D002118:Calcium