Kv1.3 is the exclusive voltage-gated K+ channel of platelets and megakaryocytes: roles in membrane potential, Ca2+ signalling and platelet count.
J Physiol
; 588(Pt 9): 1399-406, 2010 May 01.
Article
en En
| MEDLINE
| ID: mdl-20308249
ABSTRACT
A delayed rectifier voltage-gated K(+) channel (Kv) represents the largest ionic conductance of platelets and megakaryocytes, but is undefined at the molecular level. Quantitative RT-PCR of all known Kv alpha and ancillary subunits showed that only Kv1.3 (KCNA3) is substantially expressed in human platelets. Furthermore, megakaryocytes from Kv1.3(/) mice or from wild-type mice exposed to the Kv1.3 blocker margatoxin completely lacked Kv currents and displayed substantially depolarised resting membrane potentials. In human platelets, margatoxin reduced the P2X(1)- and thromboxaneA(2) receptor-evoked [Ca(2+)](i) increases and delayed the onset of store-operated Ca(2+) influx. Megakaryocyte development was normal in Kv1.3(/) mice, but the platelet count was increased, consistent with a role of Kv1.3 in apoptosis or decreased platelet activation. We conclude that Kv1.3 forms the Kv channel of the platelet and megakaryocyte, which sets the resting membrane potential, regulates agonist-evoked Ca(2+) increases and influences circulating platelet numbers.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Recuento de Plaquetas
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Plaquetas
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Megacariocitos
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Señalización del Calcio
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Canal de Potasio Kv1.3
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Potenciales de la Membrana
Límite:
Animals
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Humans
Idioma:
En
Revista:
J Physiol
Año:
2010
Tipo del documento:
Article
País de afiliación:
Reino Unido