0000000000141633
AUTHOR
Martin Heck
Calcium-Dependent Assembly of Centrin-G-Protein Complex in Photoreceptor Cells
Photoexcitation of rhodopsin activates a heterotrimeric G-protein cascade leading to cyclic GMP hydrolysis in vertebrate photoreceptors. Light-induced exchanges of the visual G-protein transducin between the outer and inner segment of rod photoreceptors occur through the narrow connecting cilium. Here we demonstrate that transducin colocalizes with the Ca(2+)-binding protein centrin 1 in a specific domain of this cilium. Coimmunoprecipitation, centrifugation, centrin overlay, size exclusion chromatography, and kinetic light-scattering experiments indicate that Ca(2+)-activated centrin 1 binds with high affinity and specificity to transducin. The assembly of centrin-G-protein complex is medi…
Economic Considerations of the Use of New Anesthetics
UNLABELLED: Cost control in anesthesia is no longer an option; it is a necessity. New anesthetics have entered the market, but economic differences in comparison to standard anesthetic regimens are not exactly known. Eighty patients undergoing either subtotal thyroidectomy or laparoscopic cholecystectomy were randomly divided into four groups, with 20 patients in each group. Group 1 received propofol 1%/sufentanil, Group 2 received desflurane/sufentanil, Group 3 received sevoflurane/sufentanil, and Group 4 received isoflurane/sufentanil (standard anesthesia) for anesthesia. A fresh gas flow of 1.5-2 L/min and 60% N2O in oxygen was used for maintenance of anesthesia, and atracurium was given…
Interaction of glutamic-acid-rich proteins with the cGMP signalling pathway in rod photoreceptors.
The assembly of signalling molecules into macromolecular complexes (transducisomes) provides specificity, sensitivity and speed in intracellular signalling pathways. Rod photoreceptors in the eye contain an unusual set of glutamic-acid-rich proteins (GARPs) of unknown function. GARPs exist as two soluble forms, GARP1 and GARP2, and as a large cytoplasmic domain (GARP' part) of the beta-subunit of the cyclic GMP-gated channel. Here we identify GARPs as multivalent proteins that interact with the key players of cGMP signalling, phosphodiesterase and guanylate cyclase, and with a retina-specific ATP-binding cassette transporter (ABCR), through four, short, repetitive sequences. In electron mic…