Shawn M. Crump

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Voltage-dependent calcium (Ca2+) channels are involved in many specialized cellular functions and are controlled by a diversity of intracellular signals. Recently, members of the RGK family of small GTPases (Rem, Rem2, Rad, Gem/Kir) have been identified as novel contributors to the regulation of L-type calcium channel activity. In this study, microarray(More)
L-type calcium channels (LTCC) impact the function of nearly all excitable cells. The classical LTCC function is to mediate trans-sarcolemmal Ca(2+) flux. This review focuses on the contribution of a mobile segment of the LTCC that regulates ion channel function, and also serves as a regulator of transcription in the nucleus. Specifically we highlight(More)
Rem, Rem2, Rad, and Gem/Kir (RGK) represent a distinct GTPase family with largely unknown physiological functions. We report here that both Rem and Rad bind directly to Ca2+ channel beta-subunits (CaV beta) in vivo. No calcium currents are recorded from human embryonic kidney 293 cells coexpressing the L type Ca2+ channel subunits CaV1.2, CaV beta 2a, and(More)
Cardiac voltage-gated L-type Ca channels (Ca(V)) are multiprotein complexes, including accessory subunits such as Ca(V)beta2 that increase current expression. Recently, members of the Rad and Gem/Kir-related family of small GTPases have been shown to decrease current, although the mechanism remains poorly defined. In this study, we evaluated the(More)
Voltage-gated calcium channels are multiprotein complexes that regulate calcium influx and are important contributors to cardiac excitability and contractility. The auxiliary beta-subunit (CaV beta) binds a conserved domain (the alpha-interaction domain (AID)) of the pore-forming CaV alpha1 subunit to modulate channel gating properties and promote cell(More)
Rem (Rad and Gem related) is a member of the RGK family of Ras-related GTPases that also includes Rad, Rem2, and Gem/Kir. All RGK proteins share structural features that are distinct from other Ras-related proteins, including several nonconservative amino acid substitutions within regions known to participate in nucleotide binding and hydrolysis and a(More)
There are twenty-five known inherited cardiac arrhythmia susceptibility genes, all of which encode either ion channel pore-forming subunits or proteins that regulate aspects of ion channel biology such as function, trafficking, and localization. The human KCNE gene family comprises five potassium channel regulatory subunits, sequence variants in each of(More)
The L-type calcium channel (LTCC) provides trigger Ca(2+) for sarcoplasmic reticulum Ca-release, and LTCC function is influenced by interacting proteins including the LTCC distal COOH terminus (DCT) and calmodulin. DCT is proteolytically cleaved and reassociates with the LTCC complex to regulate calcium channel function. DCT reduces LTCC barium current(More)
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(More)
Crump, Shawn M., Robert N. Correll, Elizabeth A. Schroder, William C. Lester, Brian S. Finlin, Douglas A. Andres, and Jonathan Satin. L-type calcium channel -subunit and protein kinase inhibitors modulate Rem-mediated regulation of current. Am J Physiol Heart Circ Physiol 291: H1959–H1971, 2006. First published April 28, 2006;(More)