Redox regulation of the yeast voltage-gated Ca channel homolog Cch1p by glutathionylation of specific cysteine residues
Authors: Avinash Chandel
Anand K Bachhawat
Journal: Journal of Cell Science (2017)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: Glutaredoxins; Glutathione S-transferase; Redox; Thioredoxins; Voltage-gated Ca2+ channels.
Affiliations: Department of Biological Sciences, Indian Institute of Science Education & Research (IISER), Sector 81, Mohali, Punjab 140306, India., Department of Biological Sciences, Indian Institute of Science Education & Research (IISER), Sector 81, Mohali, Punjab 140306, India .

Abstract:  Cch1p, the yeast homolog of the pore-forming subunit α1 of the mammalian voltage-gated Ca2+ channel (VGCC), is located on the plasma membrane and mediates the redox-dependent influx of Ca2+ Cch1p is known to undergo both rapid activation (after oxidative stress and or a change to high pH) and slow activation (after ER stress and mating pheromone activation), but the mechanism of activation is not known. We demonstrate here that both the fast activation (exposure to pH 8-8.5 or treatment with H2O2) and the slow activation (treatment with tunicamycin or α-factor) are mediated through a common redox-dependent mechanism. Furthermore, through mutational analysis of all 18 exposed cysteine residues in the Cch1p protein, we show that the four mutants C587A, C606A, C636A and C642A, which are clustered together in a common cytoplasmic loop region, were functionally defective for both fast and slow activations, and also showed reduced glutathionylation. These four cysteine residues are also conserved across phyla, suggesting a conserved mechanism of activation. Investigations into the enzymes involved in the activation reveal that the yeast glutathione S-transferase Gtt1p is involved in the glutathionylation of Cch1p, while the thioredoxin Trx2p plays a role in the Cch1p deglutathionylation. 

Retracted: No

PubPeer comments:
 Duplicated images with different exposure contrast and dimensions under different descriptions ![file] , 
 Thanks for drawing attention to the highlighted control anti-his blots. We have now pulled out the original anti-his blots, shared these original blots with the journal. We have requested correction for the inadvertent errors that occurred during compilation. The journal has responded and a suitable correction with the corrected figure will soon appear. The correction has no impact on the results and conclusions of the paper We are happy to have had the opportunity to correct the errors in the published record. , 
 2019 correction. https: jcs.biologists.org content 132 18 jcs238410.long The wrong anti-His blots were used to prepare Fig. 5C and Fig. 7G. The corrected figure panels for tunicamycin-treated cells in Fig. 5C and TRX mutants in Fig. 7G are shown here. The anti-His blot for pH=8.5 cells in Fig. 5C was vertically compressed during figure preparation and therefore has also been updated. All analysis was carried out on the correct replicate blots and is not affected by these errors. The online and PDF versions of the article have been updated and the authors apologise to readers for the errors, which do not impact the conclusions of the paper. ,