Human thromboxane A2 receptor genetic variants: in silico, in vitro and "in platelet" analysis

  • Posted on: 5 November 2014
  • By: fcoldren
TitleHuman thromboxane A2 receptor genetic variants: in silico, in vitro and "in platelet" analysis
Publication TypeJournal Article
Year of Publication2013
AuthorsGleim S, Stitham J, Tang WHo, Li H, Douville K, Chelikani P, Rade JJ, Martin KA, Hwa J
JournalPLoS One
Date Published2013
KeywordsAmino Acid Sequence, Amino Acid Substitution, Aspirin, Binding Sites, Binding, Competitive, Blood Platelets, Cell Line, Cyclooxygenase Inhibitors, Genetic Association Studies, Humans, Models, Molecular, Molecular Sequence Data, Phosphoproteins, Platelet Activation, Polymorphism, Single Nucleotide, Protein Structure, Secondary, Protein Structure, Tertiary, Proteome, Receptors, Thromboxane A2, Prostaglandin H2, Signal Transduction, Thromboxanes

Thromboxane and its receptor have emerged as key players in modulating vascular thrombotic events. Thus, a dysfunctional hTP genetic variant may protect against (hypoactivity) or promote (hyperactivity) vascular events, based upon its activity on platelets. After extensive in silico analysis, six hTP-α variants were selected (C(68)S, V(80)E, E(94)V, A(160)T, V(176)E, and V(217)I) for detailed biochemical studies based on structural proximity to key regions involved in receptor function and in silico predictions. Variant biochemical profiles ranged from severe instability (C(68)S) to normal (V(217)I), with most variants demonstrating functional alteration in binding, expression or activation (V(80)E, E(94)V, A(160)T, and V(176)E). In the absence of patient platelet samples, we developed and validated a novel megakaryocyte based system to evaluate human platelet function in the presence of detected dysfunctional genetic variants. Interestingly, variant V80E exhibited reduced platelet activation whereas A160T demonstrated platelet hyperactivity. This report provides the most comprehensive in silico, in vitro and "in platelet" evaluation of hTP variants to date and highlightscurrent inherent problems in evaluating genetic variants, with possible solutions. The study additionally provides clinical relevance to characterized dysfunctional hTP variants.

Alternate JournalPLoS ONE
PubMed ID23840660
PubMed Central IDPMC3696120
Grant ListHL074190 / HL / NHLBI NIH HHS / United States
HL115247 / HL / NHLBI NIH HHS / United States
HL117798 / HL / NHLBI NIH HHS / United States
R01 HL091013 / HL / NHLBI NIH HHS / United States