A chloroplast sulphate transporter modulates glutathione‐mediated redox cycling to regulate cell division

• DOI: 10.1111/pce.15113
• Publication Date: 2024-08-27T14:09:31Z
• Authors: Pin‐jui Huang; Yen‐Ling Lin; Chun‐Han Chen; Hsiang‐Yin Lin; Su‐Chiung Fang
• Keywords: Chlamydomonas reinhardtii; Glutathione synthetase; Glutaredoxin; GPX1

Glutathione redox cycling is important for cell cycle regulation, but its mechanisms are not well understood. We previously identified a small-sized mutant, suppressor of mat3 15-1 (smt15-1) that has elevated cellular glutathione. Here, we demonstrated SMT15 chloroplast sulphate transporter. Reducing expression γ-GLUTAMYLCYSTEINE SYNTHETASE, encoding the rate-limiting enzyme required glutathione biosynthesis, corrected size defect smt15-1 cells. Overexpressing GLUTATHIONE SYNTHETASE (GSH2) recapitulated small-size phenotype confirming role in division. Hence, may regulate concentration to modulate levels. In wild-type cells, and/or thiol-containing molecules (GSH/thiol) accumulated cytosol at G1 phase and decreased as cells entered S/M phase. While cytosolic GSH/thiol levels mutants, GSH2 overexpressors, mirrored those (accumulating during declining early phase), was specifically basal bodies mutants. Therefore, propose GSH/thiol-mediated signalling mitotic division number Chlamydomonas reinhardtii. Our findings suggest new mechanism by which regulates multiple fission C.