7f8r
From Proteopedia
Crystal structure of human soluble CLIC1 with catalytic cysteine (Cys24) in sulphonic acid form.
Structural highlights
FunctionCLIC1_HUMAN Can insert into membranes and form chloride ion channels. Channel activity depends on the pH. Membrane insertion seems to be redox-regulated and may occur only under oxydizing conditions. Involved in regulation of the cell cycle.[1] [2] [3] [4] [5] [6] [7] Publication Abstract from PubMedAscorbate is an important cellular antioxidant that gets readily oxidized to dehydroascorbate (DHA). Recycling of DHA is therefore paramount in the maintenance of cellular homeostasis and preventing oxidative stress. Dehydroascorbate reductases (DHARs), in conjunction with glutathione (GSH), carry out this vital process in eukaryotes, among which plant DHARs have garnered considerable attention. A detailed kinetic analysis of plant DHARs relative to their human counterparts is, however, lacking. Chloride intracellular channels (HsCLICs) are close homologs of plant DHARs, recently demonstrated to share their enzymatic activity. This study reports the highest turnover rate for a plant DHAR from stress adapted Pennisetum glaucum (PgDHAR). In comparison, HsCLICs 1, 3, and 4 reduced DHA at a significantly lower rate. We further show that the catalytic cysteine from both homologs was susceptible to varying degrees of oxidation, validated by crystal structures and mass-spectrometry. Our findings may have broader implications on crop improvement using pearl millet DHAR vis-a-vis discovery of cancer therapeutics targeting Vitamin-C recycling capability of human CLICs. Comparative kinetic analysis of ascorbate (Vitamin-C) recycling dehydroascorbate reductases from plants and humans.,Das BK, Kumar A, Sreekumar SN, Ponraj K, Gadave K, Kumar S, Murali Achary VM, Ray P, Reddy MK, Arockiasamy A Biochem Biophys Res Commun. 2021 Dec 29;591:110-117. doi:, 10.1016/j.bbrc.2021.12.103. PMID:35007834[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. Loading citation details.. Citations No citations found References
|
|