Modified cardiovascular L-type channels in mice lacking the voltage-dependent Ca2+ channel beta3 subunit

The beta subunits of voltage-dependent calcium channels are known to modify calcium channel currents through pore-forming alpha1 subunits. Of the four beta subunits reported to date, the beta3 subunit is highly expressed in smooth muscle cells and is thought to consist of L-type calcium channels. To determine the role of the beta3 subunit in the voltage-dependent calcium channels of the cardiovascular system in situ, we performed a series of experiments in beta3-null mice. Western blot analysis indicated a significant reduction in expression of the alpha1 subunit in the plasma membrane of beta3-null mice. Dihydropyridine binding experiments also revealed a significant decrease in the calcium channel population in the aorta. Electrophysiological analyses indicated a 30% reduction in Ca2+ channel current density, a slower inactivation rate, and a decreased dihydropyridine-sensitive current in beta3-null mice. The reductions in the peak current density and inactivation rate were reproduced in vitro by co-expression of the calcium channel subunits in Chinese hamster ovary cells. Despite the reduced channel population, beta3-null mice showed normal blood pressure, whereas a significant reduction in dihydropyridine responsiveness was observed. A high salt diet significantly elevated blood pressure only in the beta3-null mice and resulted in hypertrophic changes in the aortic smooth muscle layer and cardiac enlargement. In conclusion, this study demonstrates the involvement and importance of the beta3 subunit of voltage-dependent calcium channels in the cardiovascular system and in regulating channel populations and channel properties in vascular smooth muscle cells.

Medienart:

Artikel

Erscheinungsjahr:

2003

Erschienen:

2003

Enthalten in:

Zur Gesamtaufnahme - volume:278

Enthalten in:

The Journal of biological chemistry - 278(2003), 44 vom: 31. Okt., Seite 43261-7

Sprache:

Englisch

Beteiligte Personen:

Murakami, Manabu [VerfasserIn]
Yamamura, Hisao [VerfasserIn]
Suzuki, Takashi [VerfasserIn]
Kang, Myoung-Goo [VerfasserIn]
Ohya, Susumu [VerfasserIn]
Murakami, Agnieszka [VerfasserIn]
Miyoshi, Ichiro [VerfasserIn]
Sasano, Hironobu [VerfasserIn]
Muraki, Katsuhiko [VerfasserIn]
Hano, Takuzou [VerfasserIn]
Kasai, Noriyuki [VerfasserIn]
Nakayama, Shinnsuke [VerfasserIn]
Campbell, Kevin P [VerfasserIn]
Flockerzi, Veit [VerfasserIn]
Imaizumi, Yuji [VerfasserIn]
Yanagisawa, Teruyuki [VerfasserIn]
Iijima, Toshihiko [VerfasserIn]

Themen:

1,4-dihydropyridine
147336-22-9
7M8K3P6I89
Calcium
Calcium Channels
Calcium Channels, L-Type
Dihydropyridines
Green Fluorescent Proteins
Journal Article
Luminescent Proteins
Research Support, Non-U.S. Gov't
SY7Q814VUP

Anmerkungen:

Date Completed 24.12.2003

Date Revised 09.02.2021

published: Print-Electronic

Citation Status MEDLINE

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM126728828