title: Ryanodine receptor 1 mediates Ca2+ transport and influences the biomechanical properties in RBCs.
abstract: Ryanodine receptors (RyRs) are a family of Ca2+ channel proteins that mediate the massive release of Ca2+ from the endoplasmic reticulum into the cytoplasma. In the present study, we manipulated the incorporation of RyR1 into RBC membrane and investigated its influences on the intracellular Ca2+ ([Ca2+](in)) level and the biomechanical properties in RBCs. The incorporation of RyR1 into RBC membranes was demonstrated by both immunofluorescent staining and the change of [Ca2+](in) of RBCs. In the presence of RyR1, [Ca2+](in) showed biphasic changes, i.e., it increased with the extracellular Ca2+ ([Ca2+](ex)) up to 5muM and then decreased with the further increase of [Ca2+](ex). However, [Ca2+](in) remained constant in the absence of the RyR1. The results of biomechanical measurements on RBCs, including deformability, osmotic fragility, and membrane microviscosity, reflected similar biphasic changes of [Ca2+](in) mediated by RyR1 with the increases of [Ca2+](ex). Therefore, it is believed that RyR1 can incorporate into RBC membrane in vitro, and mediate Ca2+ influx, and then regulate RBC biomechanical properties. This information suggests that RBCs may serve as a model to study the function of RyR1 as a Ca2+ release channel.
authors.affiliation: Department of Biophysics, Health Science Center, Peking University, Beijing 100191, PR China.
authors.forename: Xianwei
authors.initials: X
authors.lastname: Wang
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: Zhiyu
authors.initials: Z
authors.lastname: Tang
authors.forename: Weijuan
authors.initials: W
authors.lastname: Yao
authors.forename: Xiao
authors.initials: X
authors.lastname: Liu
authors.forename: Risheng
authors.initials: R
authors.lastname: Wei
authors.forename: Xifu
authors.initials: X
authors.lastname: Wang
authors.forename: Weibo
authors.initials: W
authors.lastname: Ka
authors.forename: Dagong
authors.initials: D
authors.lastname: Sun
authors.forename: Dongqi
authors.initials: D
authors.lastname: He
authors.forename: Zongyao
authors.initials: Z
authors.lastname: Wen
authors.forename: Shu
authors.initials: S
authors.lastname: Chien
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D002478:Cells, Cultured; D055119:Elastic Modulus / Q000502:physiology; D004910:Erythrocyte Membrane / Q000502:physiology*; D004912:Erythrocytes / Q000502:physiology*; D008560:Membrane Fluidity / Q000502:physiology; D011817:Rabbits; D019837:Ryanodine Receptor Calcium Release Channel / Q000502:physiology*; D013314:Stress, Mechanical; D014783:Viscosity
chemical_list: D019837:Ryanodine Receptor Calcium Release Channel; D002118:Calcium