The mechanism of import-competent precursor protein-induced inactivation of a 50-pS anion channel of the chloroplast envelope is investigated using single-channel recordings. The inactivation by precursor protein is the result of the induction of a long-lived closed state of the channel. The mean duration of this state does not depend on precursor concentration. From this it can be concluded th...

Qu, Yongxia, Ghayath Baroudi, Yuankun Yue, Nabil El-Sherif, and Mohamed Boutjdir. Localization and modulation of 1D (Cav1.3) L-type Ca channel by protein kinase A. Am J Physiol Heart Circ Physiol 288: H2123–H2130, 2005. First published December 22, 2004; doi:10.1152/ajpheart.01023.2004.— 1D L-type Ca channel was assumed to be of neuroendocrine origin only; however, 1D L-type Ca channel knockout...

Protein translocation across the mitochondrial inner membrane is mediated by the TIM23 complex. While its central component, Tim23, is believed to form a protein-conducting channel, the regions of this subunit that face the imported protein are unknown. To examine Tim23 structure and environment in intact membranes at high resolution, various derivatives, each with a single, environment-sensiti...

We used the patch-clamp technique to study the effect of insulin-like growth factor I (IGF-I) on the apical 70-pS K channel in the isolated thick ascending limb (TAL) of the rat kidney. The isolated TAL was cut open to gain access to the apical membrane. Addition of 25 nM IGF-I stimulates the apical 70-pS K channel and increases channel activity, defined by the product of channel open probabili...

The iberiotoxin-sensitive large conductance voltage- and Ca(2+)-activated potassium (BK) channels (maxi-K(+)-channels) hyperpolarize the cell membrane thus supporting Ca(2+) entry through Ca(2+)-release activated Ca(2+) channels. Janus kinase-2 (JAK2) has been identified as novel regulator of ion transport. To explore whether JAK2 participates in the regulation of BK channels, cRNA encoding Ca(...

Hypothalamic proopiomelanocortin (POMC) neurons are critical for controlling homeostatic functions in mammals. We used a transgenic mouse model in which the POMC neurons were labeled with enhanced-green fluorescent protein (EGFP) to perform visualized, whole-cell patch recordings from pre-pubertal female hypothalamic slices. The mouse POMC-EGFP neurons expressed the same endogenous conductance ...

Human ether-a-go-go related-gene K⁺ channels (hERG) participate in the regulation of tumor cell proliferation and apoptosis. HERG channel activity is up-regulated by growth factors. Kinases sensitive to growth factor signaling include the serine/threonine protein kinase B-RAF. The present study thus explored whether B-RAF influences hERG channel expression and activity. To this end, hERG channe...

Hypothalamic proopiomelanocortin (POMC) neurons are critical for controlling homeostatic functions in mammals. We used a transgenic mouse model in which the POMC neurons were labeled with enhanced-green fluorescent protein (EGFP) to perform visualized, whole-cell patch recordings from pre-pubertal female hypothalamic slices. The mouse POMC-EGFP neurons expressed the same endogenous conductance ...