| Autor: |
Babur Ö; Department of Molecular and Medical Genetics, Oregon Health & Science University , Portland, Oregon.; Computational Biology Program, Oregon Health & Science University , Portland, Oregon., Ngo ATP; Department of Biomedical Engineering, Oregon Health & Science University , Portland, Oregon., Rigg RA; Department of Biomedical Engineering, Oregon Health & Science University , Portland, Oregon., Pang J; Department of Biomedical Engineering, Oregon Health & Science University , Portland, Oregon., Rub ZT; Department of Biomedical Engineering, Oregon Health & Science University , Portland, Oregon., Buchanan AE; Knight Cardiovascular Institute, School of Medicine, Oregon Health & Science University , Portland, Oregon., Mitrugno A; Department of Biomedical Engineering, Oregon Health & Science University , Portland, Oregon., David LL; Department of Biochemistry and Molecular Biology, Oregon Health & Science University , Portland, Oregon., McCarty OJT; Department of Biomedical Engineering, Oregon Health & Science University , Portland, Oregon.; Department of Cell, Developmental, & Cancer Biology, Oregon Health & Science University , Portland, Oregon.; Division of Hematology & Medical Oncology, Oregon Health & Science University , Portland, Oregon., Demir E; Department of Molecular and Medical Genetics, Oregon Health & Science University , Portland, Oregon.; Computational Biology Program, Oregon Health & Science University , Portland, Oregon., Aslan JE; Department of Biochemistry and Molecular Biology, Oregon Health & Science University , Portland, Oregon.; Knight Cardiovascular Institute, School of Medicine, Oregon Health & Science University , Portland, Oregon. |
| Abstrakt: |
Upon encountering physiological cues associated with damaged or inflamed endothelium, blood platelets set forth intracellular responses to ultimately support hemostatic plug formation and vascular repair. To gain insights into the molecular events underlying platelet function, we used a combination of interactome, pathway analysis, and other systems biology tools to analyze associations among proteins functionally modified by reversible phosphorylation upon platelet activation. While an interaction analysis mapped out a relative organization of intracellular mediators in platelet signaling, pathway analysis revealed directional signaling relations around protein kinase C (PKC) isoforms and mitogen-activated protein kinases (MAPKs) associated with platelet cytoskeletal dynamics, inflammatory responses, and hemostatic function. Pathway and causality analysis further suggested that platelets activate a specific p38-MK2 axis to phosphorylate RTN4 (reticulon-4, also known as Nogo), a Bcl-xl sequestration protein and critical regulator of endoplasmic reticulum (ER) physiology. In vitro, we find that platelets drive a p38-MK2-RTN4-Bcl-xl pathway associated with the regulation of the ER and platelet phosphatidylserine exposure. Together, our results support the use of pathway tools in the analysis of omics data sets as a means to help generate novel, mechanistic, and testable hypotheses for platelet studies while uncovering RTN4 as a putative regulator of platelet cell physiological responses. |
