title: Cell cycle-dependent expression of Kv1.5 is involved in myoblast proliferation.
abstract: Voltage-dependent K(+) channels (Kv) are involved in the proliferation of many types of cells, but the mechanisms by which their activity is related to cell growth remain unclear. Kv antagonists inhibit the proliferation of mammalian cells, which is of physiological relevance in skeletal muscle. Although myofibres are terminally differentiated, some resident myoblasts may re-enter the cell cycle and proliferate. Here we report that the expression of Kv1.5 is cell-cycle dependent during myoblast proliferation. In addition to Kv1.5 other Kv, such as Kv1.3, are also up-regulated. However, pharmacological evidence mainly implicates Kv1.5 in myoblast growth. Thus, the presence of S0100176, a Kv antagonist, but not margatoxin and dendrotoxin, led to cell cycle arrest during the G(1)-phase. The use of selective cell cycle blockers showed that Kv1.5 was transiently accumulated during the early G(1)-phase. Furthermore, while myoblasts treated with S0100176 expressed low levels of cyclin A and D(1), the expression of p21(cip-1) and p27(kip1), two cyclin-dependent kinase inhibitors, increased. Our results indicate that the cell cycle-dependent expression of Kv1.5 is involved in skeletal muscle cell proliferation.
authors.affiliation: Molecular Physiology Laboratory, Departament de Bioquímica i Biología Molecular, Institut de Biomedicina, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Núria
authors.initials: N
authors.lastname: Villalonga
authors.forename: Ramón
authors.initials: R
authors.lastname: Martínez-Mármol
authors.forename: Meritxell
authors.initials: M
authors.lastname: Roura-Ferrer
authors.forename: Miren
authors.initials: M
authors.lastname: David
authors.forename: Carmen
authors.initials: C
authors.lastname: Valenzuela
authors.forename: Concepció
authors.initials: C
authors.lastname: Soler
authors.forename: Antonio
authors.initials: A
authors.lastname: Felipe
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000235:genetics; D002460:Cell Line; D049109:Cell Proliferation; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000502:physiology; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000502:physiology; D015870:Gene Expression; D051664:Kv1.3 Potassium Channel / Q000235:genetics / Q000378:metabolism; D051666:Kv1.5 Potassium Channel / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D032448:Myoblasts, Skeletal / Q000166:cytology / Q000378:metabolism*; D051381:Rats
chemical_list: D050759:Cyclin-Dependent Kinase Inhibitor p21; D051664:Kv1.3 Potassium Channel; D051666:Kv1.5 Potassium Channel; D050760:Cyclin-Dependent Kinase Inhibitor p27