Ca2+ permeability of the plasma membrane induced by rotavirus infection in cultured cells is inhibited by tunicamycin and brefeldin A.
Rotavirus infection of cultured cells induces a progressive increase in plasma membrane permeability to Ca2+. The viral product responsible for this effect is not known. We have used tunicamycin and brefeldin A to prevent glycosylation and membrane traffic and study the involvement of viral glycoproteins, NSP4 and/or VP7, in rotavirus-infected HT29 and MA104 cells. In infected cells, we observed an increase of plasma membrane Ca2+ permeability and a progressive depletion of agonist-releasable ER pools measured with fura 2 and an enhancement of total Ca2+ content measured as 45Ca2+ uptake. Tunicamycin inhibited the increase in membrane Ca2+ permeability, induced a depletion of agonist-releasable and 45Ca2+-sequestered pools. Brefeldin A inhibited the increase of Ca2+ permeability and the increase in 45Ca2+ uptake induced by infection. We propose that the glycosylated viral product NSP4 (and/or VP7) travels to the plasma membrane to form a Ca2+ channel and hence elevate Ca2+ permeability.
Ruiz
Marie Christine
MC
Laboratorio de Fisiología Gastrointestinal, Instituto Venezolano de Investigaciones Científicas, Caracas 1020A, Venezuela. mclr@ivic.ve
Díaz
Yuleima
Y
Peña
Franshelle
F
Aristimuño
Olga C
OC
Chemello
Maria Elena
ME
Michelangeli
Fabian
F
D000818:Animals; D000956:Antigens, Viral / Q000502:physiology; D020126:Brefeldin A / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D036022:Capsid Proteins / Q000502:physiology; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000187:drug effects* / Q000502:physiology*; D012321:DNA-Directed RNA Polymerases / Q000502:physiology; D006031:Glycosylation / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D012401:Rotavirus / Q000502:physiology*; D014415:Tunicamycin / Q000494:pharmacology*; D017361:Viral Nonstructural Proteins / Q000502:physiology
D000956:Antigens, Viral; D036022:Capsid Proteins; C050779:VP7 protein, Rotavirus; D017361:Viral Nonstructural Proteins; D014415:Tunicamycin; D020126:Brefeldin A; D012321:DNA-Directed RNA Polymerases; D002118:Calcium