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Das BK, Khan WA, Sreekumar SN, Ponraj K, Achary VMM, Reddy ES, Balasubramaniam D, Chandele A, Reddy MK, Arockiasamy A. Plant dehydroascorbate reductase moonlights as membrane integrated ion channel. Arch Biochem Biophys 2023; 741:109603. [PMID: 37084805 DOI: 10.1016/j.abb.2023.109603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 04/03/2023] [Accepted: 04/17/2023] [Indexed: 04/23/2023]
Abstract
Plant dehydroascorbate reductases (DHARs) are only known as soluble antioxidant enzymes of the ascorbate-glutathione pathway. They recycle ascorbate from dehydroascorbate, thereby protecting plants from oxidative stress and the resulting cellular damage. DHARs share structural GST fold with human chloride intracellular channels (HsCLICs) which are dimorphic proteins that exists in soluble enzymatic and membrane integrated ion channel forms. While the soluble form of DHAR has been extensively studied, the existence of a membrane integrated form remains unknown. We demonstrate for the first time using biochemistry, immunofluorescence confocal microscopy, and bilayer electrophysiology that Pennisetum glaucum DHAR (PgDHAR) is dimorphic and is localized to the plant plasma membrane. In addition, membrane translocation increases under induced oxidative stress. Similarly, HsCLIC1 translocates more into peripheral blood mononuclear cells (PBMCs) plasma membrane under induced oxidative stress conditions. Moreover, purified soluble PgDHAR spontaneously inserts and conducts ions in reconstituted lipid bilayers, and the addition of detergent facilitates insertion. In addition to the well-known soluble enzymatic form, our data provides conclusive evidence that plant DHAR also exists in a novel membrane-integrated form. Thus, the structure of DHAR ion channel form will help gain deeper insights into its function across various life forms.
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Affiliation(s)
- Bhaba Krishna Das
- Membrane Protein Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Wajahat Ali Khan
- Membrane Protein Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| | - Sreeshma Nellootil Sreekumar
- Membrane Protein Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India; Department of Biotechnology, Jamia Hamdard University, New Delhi, 110062, India
| | - Kannapiran Ponraj
- Membrane Protein Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - V Mohan Murali Achary
- Crop Improvement Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Elluri Seetharami Reddy
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India; Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - D Balasubramaniam
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Anmol Chandele
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Malireddy K Reddy
- Crop Improvement Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Arulandu Arockiasamy
- Membrane Protein Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
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