Thylakoid localized bestrophin-like proteins are essential for the CO 2 concentrating mechanism of Chlamydomonas reinhardtii
| العنوان: | Thylakoid localized bestrophin-like proteins are essential for the CO 2 concentrating mechanism of Chlamydomonas reinhardtii |
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| المؤلفون: | Spencer G. Lemoine, Ashwani K Rai, Camille I. Prejean, Ananya Mukherjee, James V. Moroney, Gary Yates, Luke C. M. Mackinder, Chun Sing Lau, Charlotte Elizabeth Walker, Thomas Emrich-Mills, David J. Vinyard |
| المصدر: | Proceedings of the National Academy of Sciences. 116:16915-16920 |
| بيانات النشر: | Proceedings of the National Academy of Sciences, 2019. |
| سنة النشر: | 2019 |
| مصطلحات موضوعية: | 0106 biological sciences, 0301 basic medicine, Multidisciplinary, biology, Chemistry, RuBisCO, Chlamydomonas, Chlamydomonas reinhardtii, biology.organism_classification, 01 natural sciences, Cell biology, Chloroplast thylakoid, Chloroplast, 03 medical and health sciences, Chloroplast stroma, 030104 developmental biology, Thylakoid, biology.protein, Carbonic anhydrase 3, 010606 plant biology & botany |
| الوصف: | The green alga Chlamydomonas reinhardtii possesses a CO2 concentrating mechanism (CCM) that helps in successful acclimation to low CO2 conditions. Current models of the CCM postulate that a series of ion transporters bring HCO3− from outside the cell to the thylakoid lumen, where the carbonic anhydrase 3 (CAH3) dehydrates accumulated HCO3− to CO2, raising the CO2 concentration for Ribulose bisphosphate carboxylase/oxygenase (Rubisco). Previously, HCO3− transporters have been identified at both the plasma membrane and the chloroplast envelope, but the transporter thought to be on the thylakoid membrane has not been identified. Three paralogous genes (BST1, BST2, and BST3) belonging to the bestrophin family have been found to be up-regulated in low CO2 conditions, and their expression is controlled by CIA5, a transcription factor that controls many CCM genes. YFP fusions demonstrate that all 3 proteins are located on the thylakoid membrane, and interactome studies indicate that they might associate with chloroplast CCM components. A single mutant defective in BST3 has near-normal growth on low CO2, indicating that the 3 bestrophin-like proteins may have redundant functions. Therefore, an RNA interference (RNAi) approach was adopted to reduce the expression of all 3 genes at once. RNAi mutants with reduced expression of BST1–3 were unable to grow at low CO2 concentrations, exhibited a reduced affinity to inorganic carbon (Ci) compared with the wild-type cells, and showed reduced Ci uptake. We propose that these bestrophin-like proteins are essential components of the CCM that deliver HCO3− accumulated in the chloroplast stroma to CAH3 inside the thylakoid lumen. |
| تدمد: | 1091-6490 0027-8424 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_________::48b6953200a861ca6b02b6299682c6fcTest https://doi.org/10.1073/pnas.1909706116Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi...........48b6953200a861ca6b02b6299682c6fc |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 10916490 00278424 |
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