Analysis of the CREBBP cistrome in human embryonic kidney 293 cells

Abstract Background Bupivacaine blocks many ion channels in the heart muscle, causing severe cardiotoxicity. Small-conductance calcium-activated potassium type 2 channels (SK2 channels) are widely distributed in the heart cells and are involved in relevant physiological functions. However, whether bupivacaine can inhibit SK2 channels is still unclear. This study investigated the effect of bupivacaine on SK2 channels. Methods The SK2 channel gene was transfected into human embryonic kidney 293 cells (HEK-293 cells) with Lipofectamine 2000. The whole-cell patch-clamp technique was used to examine the effect of bupivacaine on SK2 channels. The concentration–response relationship of bupivacaine for inhibiting SK2 currents (0 mV) was fitted to a Hill equation, and the half-maximal inhibitory concentration (IC50) value was determined. Results Bupivacaine inhibited the SK2 channels reversibly in a dose-dependent manner. The IC50 value of bupivacaine, ropivacaine, and lidocaine on SK2 currents was 16.5, 46.5, and 77.8µM, respectively. The degree of SK2 current inhibition by bupivacaine depended on the intracellular concentration of free calcium. Conclusions The results of this study suggested the inhibitory effect of bupivacaine on SK2 channels. Future studies should explore the effects of SK2 on bupivacaine cardiotoxicity.

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Protein Tyrosine Phosphatase-1B Dephosphorylation of the Insulin Receptor Occurs in a Perinuclear Endosome Compartment in Human Embryonic Kidney 293 Cells

Journal of Biological Chemistry ◽

10.1074/jbc.m309600200 ◽

2004 ◽

Vol 279 (13) ◽

pp. 12868-12875 ◽

Cited By ~ 58

Author(s):

Yolanda Romsicki ◽

Mark Reece ◽

Jacques-Yves Gauthier ◽

Ernest Asante-Appiah ◽

Brian P. Kennedy

Keyword(s):

Insulin Receptor ◽

Protein Tyrosine Phosphatase ◽

Tyrosine Phosphatase ◽

Protein Tyrosine Phosphatase 1B ◽

Human Embryonic Kidney ◽

Protein Tyrosine ◽

293 Cells

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Endothelin-B receptors activate Gα13

AJP Cell Physiology ◽

10.1152/ajpcell.1999.276.4.c930 ◽

1999 ◽

Vol 276 (4) ◽

pp. C930-C937 ◽

Cited By ~ 32

Author(s):

Kenichiro Kitamura ◽

Naoki Shiraishi ◽

William D. Singer ◽

Mary E. Handlogten ◽

Kimio Tomita ◽

...

Keyword(s):

G Protein ◽

G Proteins ◽

Guanine Nucleotides ◽

Heterotrimeric G Proteins ◽

Human Embryonic Kidney ◽

Cellular Effects ◽

293 Cells ◽

Specific Antagonist ◽

Α Chain ◽

Endothelin B

Endothelin (ET) receptors activate heterotrimeric G proteins that are members of the Gi, Gq, and Gs families but may also activate members of other families such as Gα12/13. Gα13 has multiple complex cellular effects that are similar to those of ET. We studied the ability of ET receptors to activate Gα13 using an assay for G protein α-chain activation that is based on the fact that an activated (GTP-bound) α-chain is resistant to trypsinization compared with an inactive (GDP-bound) α-chain. Nonhydrolyzable guanine nucleotides and AlMgF protected Gα13 from degradation by trypsin. In membranes from human embryonic kidney 293 cells that coexpress ETB receptors and α13, ET-3 and 5′-guanylylimidodiphosphate [Gpp(NH)p] increased the protection of α13 compared with Gpp(NH)p alone. The specificity of ETBreceptor-α13 coupling was documented by showing that β2receptors and isoproterenol or ETAreceptors and ET-1 did not activate α13 and that a specific antagonist for ETB receptors blocked ET-3-dependent activation of α13.

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