Rem-GTPase regulates cardiac myocyte L-type calcium current.

Rationale: The L-type calcium channels (LTCC) are critical for maintaining Ca(2+)-homeostasis. In heterologous expression studies, the RGK-class of Ras-related G-proteins regulates LTCC function; however, the physiological relevance of RGK-LTCC interactions is untested.

Objective: In this report we test the hypothesis that the RGK protein, Rem, modulates native Ca(2+) current (I(Ca,L)) via LTCC in murine cardiomyocytes.

Divergent action potential morphologies reveal nonequilibrium properties of human cardiac Na channels.

Objective: Fast inward Na current (I(Na)) carried by the voltage-gated Na channel (Na(V)1.5) is critical for action potential (AP) propagation and the rapid upstroke of the cardiac AP. In addition, a small fraction of Na(V)1.