1
|
Chauhan M, Arshi SA, Narayanan N, Arfin HU, Sharma A. A mechanistic insight on how Compromised Hydrolysis of Triacylglycerol 7 (CHT7) restrains the involvement of it's CXC domain from quiescence repression. Int J Biol Macromol 2024; 265:130844. [PMID: 38484809 DOI: 10.1016/j.ijbiomac.2024.130844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 03/03/2024] [Accepted: 03/11/2024] [Indexed: 03/18/2024]
Abstract
CHT7 is a regulator of quiescence repression in Chlamydomonas reinhardtii. Initially, CHT7's repression activity was thought to be managed by its DNA-binding CXC domain. Later, it was found that the CHT7-CXC domain is dispensable for CHT7's activities. Rather, CHT7's predicted protein domains were proposed to be involved in regulation activities by binding to other repressors in the cell. Yet, it remains unclear why and how CHT7 refrains its CXC domain from participating in any transcriptional activities. The question becomes more intriguing, since CXC binding regions are available in promoter regions of some of the misregulated genes in CHT7 mutant (cht7). Through biophysical experiments and molecular dynamics approaches, we studied the DNA recognition behavior of CHT7-CXC. The results indicate that this domain possesses sequence selectivity due to the differential binding abilities of its subdomains. Further, to understand if the case is that CXC loses its DNA binding capabilities in the vicinity of other repressors, we examined CHT7-CXC's DNA binding stability under the spatial constraint conditions created through fusing CHT7-CXC with AsLOV2. The results show limited ability of CHT7-CXC to withstand steric forces and provide insights to why and how algal cells may hold back CHT7-CXC's indulgence in quiescence repression. CLASSIFICATIONS: Biological Sciences, Biophysics and Computational Biology.
Collapse
Affiliation(s)
- Manisha Chauhan
- Multidisciplinary Centre for Advanced Research and Studies, Jamia Millia Islamia, New Delhi 110025, India
| | - Syeda Amna Arshi
- Multidisciplinary Centre for Advanced Research and Studies, Jamia Millia Islamia, New Delhi 110025, India
| | - Naveen Narayanan
- Regional Centre for Biotechnology, NCR-Cluster Faridabad, Haryana 121001, India
| | - Haseeb Ul Arfin
- Multidisciplinary Centre for Advanced Research and Studies, Jamia Millia Islamia, New Delhi 110025, India
| | - Amit Sharma
- Multidisciplinary Centre for Advanced Research and Studies, Jamia Millia Islamia, New Delhi 110025, India.
| |
Collapse
|
2
|
Tsuji Y, Kinoshita A, Tsukahara M, Ishikawa T, Shinkawa H, Yamano T, Fukuzawa H. A YAK1-type protein kinase, triacylglycerol accumulation regulator 1, in the green alga Chlamydomonas reinhardtii is a potential regulator of cell division and differentiation into gametes during photoautotrophic nitrogen deficiency. J GEN APPL MICROBIOL 2022. [PMID: 36002293 DOI: 10.2323/jgam.2022.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Yet another kinase (YAK) 1 is a conserved eukaryotic protein kinase coordinating growth and development. We previously isolated a mutant of Chlamydomonas reinhardtii defective in the YAK1 ortholog triacylglycerol (TAG) accumulation regulator 1 (TAR1). The mutant tar1-1 displayed higher levels of chlorophyll, starch, TAG, and biomass than the parental strain C9 (renamed as C9-3) in photoautotrophic nitrogen (N)-deficient conditions. However, we found that the parental C9-3 showed faster chlorosis upon N-deficiency than the original C9 (C9-1) freshly recovered from cryopreservation, suggesting that C9-3 had acquired particular characteristics during long-term subculturing. To exclude phenotypes dependent on a particular parental strain, we newly created tar1 mutants from two wild-types, C9-1 and CC 125. Like tar1-1, the new tar1 mutants showed higher levels of chlorophyll and TAG/starch than the parental strain. Upon removal of N, Chlamydomonas cells divide once before ceasing further division. Previously, the single division after N-removal was arrested in tar1-1 in photomixotrophic conditions, but this phenotype was not observed in photoautotrophic conditions because of the particular characteristics of the parental C9-3. However, using C9- 1 and CC-125 as parental strains, we showed that cell division after N-removal was impaired in new tar1 mutants in photoautotrophic conditions. Consistent with the view that the division under N-deficiency is necessary for gametic differentiation, new tar1 mutants showed lower mating efficiency than the parental strains. Taken together, TAR1 was suggested to promote differentiation into gametes through the regulation of cell division in response to N-deficiency.
Collapse
Affiliation(s)
| | | | | | | | - Haruka Shinkawa
- Graduate Study of Biostudies, Kyoto University.,Present address: Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University
| | | | | |
Collapse
|
3
|
Lin YT, Takeuchi T, Youk B, Umen J, Sears BB, Benning C. Chlamydomonas CHT7 is involved in repressing DNA replication and mitotic genes during synchronous growth. G3 GENES|GENOMES|GENETICS 2022; 12:6523978. [PMID: 35137070 PMCID: PMC8895990 DOI: 10.1093/g3journal/jkac023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 01/21/2022] [Indexed: 11/13/2022]
Abstract
In the green alga Chlamydomonas reinhardtii, regulation of the cell cycle in response to external cues is critical for survival in a changing environment. The loss of the nuclear COMPROMISED HYDROLYSIS OF TRIACYLGLYCEROLS 7 (CHT7) protein affects the expression of many genes especially in response to nitrogen availability. Cells lacking CHT7 exhibit abnormal cell morphology following nitrogen deprivation and fail to resume normal cell division after N resupply. To investigate the function of CHT7 in the regulation of cell cycle-related pathways, cells were synchronized, and RNA-seq analysis was performed during various stages of the cell cycle. In the cht7 mutant following nitrogen deprivation, the cells were not dividing, but a subset of cell cycle genes involved in DNA replication and mitosis were found to be derepressed, suggesting that the CHT7 protein plays a role in cell cycle regulation that is opposite to that of the mitotic cyclin-dependent kinases. Furthermore, genes for cell wall synthesis and remodeling were found to be abnormally induced in nondividing cht7 cells; this misregulation may deplete cellular resources and thus contribute to cell death following nitrogen deprivation. Lastly, 43 minimally characterized kinases were found to be highly misregulated in cht7. Further analysis suggested that some of these CHT7-regulated kinases may be related to the MAP3K and Aurora-like kinases, while others are unique. Together, these results suggest a role of CHT7 in transcriptional regulation of the cell cycle and reveal several pathways and genes whose expression appears to be subject to a CHT7-mediated regulatory network.
Collapse
Affiliation(s)
- Yang-Tsung Lin
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Tomomi Takeuchi
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Brian Youk
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - James Umen
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA
| | - Barbara B Sears
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Christoph Benning
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA
| |
Collapse
|
4
|
Saggere RMS, Lee CWJ, Chan ICW, Durnford DG, Nedelcu AM. A life-history trade-off gene with antagonistic pleiotropic effects on reproduction and survival in limiting environments. Proc Biol Sci 2022; 289:20212669. [PMID: 35078364 PMCID: PMC8790358 DOI: 10.1098/rspb.2021.2669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Although life-history trade-offs are central to life-history evolution, their mechanistic basis is often unclear. Traditionally, trade-offs are understood in terms of competition for limited resources among traits within an organism, which could be mediated by signal transduction pathways at the level of cellular metabolism. Nevertheless, trade-offs are also thought to be produced as a consequence of the performance of one activity generating negative consequences for other traits, or the result of genes or pathways that simultaneously regulate two life-history traits in opposite directions (antagonistic pleiotropy), independent of resource allocation. Yet examples of genes with antagonistic effects on life-history traits are limited. This study provides direct evidence for a gene-RLS1, that is involved in increasing survival in nutrient-limiting environments at a cost to immediate reproduction in the single-celled photosynthetic alga, Chlamydomonas reinhardtii. Specifically, we show that RLS1 mutants are unable to properly suppress their reproduction in phosphate-deprived conditions. Although these mutants have an immediate reproductive advantage relative to the parental strain, their long-term survival is negatively affected. Our data suggest that RLS1 is a bona fide life-history trade-off gene that suppresses immediate reproduction and ensures survival by downregulating photosynthesis in limiting environments, as part of the general acclimation response to nutrient deprivation in photosynthetic organisms.
Collapse
Affiliation(s)
- Rani M. S. Saggere
- Biology Department, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, Canada E3B 5A3
| | - Christopher W. J. Lee
- Biology Department, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, Canada E3B 5A3
| | - Irina C. W. Chan
- Biology Department, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, Canada E3B 5A3
| | - Dion G. Durnford
- Biology Department, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, Canada E3B 5A3
| | - Aurora M. Nedelcu
- Biology Department, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, Canada E3B 5A3
| |
Collapse
|
5
|
Zhang J, Shi J, Yuan C, Liu X, Du G, Fan R, Zhang B. MicroRNA Expression Profile Analysis of Chlamydomonas reinhardtii during Lipid Accumulation Process under Nitrogen Deprivation Stresses. Bioengineering (Basel) 2021; 9:bioengineering9010006. [PMID: 35049715 PMCID: PMC8773410 DOI: 10.3390/bioengineering9010006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/14/2021] [Accepted: 12/21/2021] [Indexed: 11/30/2022] Open
Abstract
Lipid accumulation in various microalgae has been found induced by nitrogen deprivation, and it controls many different genes expression. Yet, the underlying molecular mechanisms still remain largely unknown. MicroRNA (miRNAs) play a critical role in post-transcriptional gene regulation. In this study, miRNAs were hypothesized involved in lipid accumulation by nitrogen deprivation. A deep-sequencing platform was used to explore miRNAs-mediated responses induced by nitrogen deprivation in Chlamydomonas reinhardtii. The eukaryotic orthologous groups of proteins (KOG) function in the predicted target genes of miRNA with response to nitrogen deprivation were mainly involved in signal transduction mechanisms, including transcription, lipid transport, and metabolism. A total of 109 miRNA were predicted, including 79 known miRNA and 30 novel miRNA. A total of 29 miRNAs showed significantly differential expressions after nitrogen deprivation, and most of them were upregulated. A total of 10 miRNAs and their targeting genes might involve in lipid transport and metabolism biological process. This study first investigates nitrogen deprivation-regulated miRNAs in microalgae and broadens perspectives on miRNAs importance in microalgae lipid accumulation via nitrogen deprivation. This study provides theoretical guidance for the application of microalgae in bio-oil engineering production.
Collapse
Affiliation(s)
- Jingxian Zhang
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai 201210, China; (J.Z.); (J.S.); (C.Y.); (X.L.); (G.D.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiping Shi
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai 201210, China; (J.Z.); (J.S.); (C.Y.); (X.L.); (G.D.)
- University of Chinese Academy of Sciences, Beijing 100049, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Chenyang Yuan
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai 201210, China; (J.Z.); (J.S.); (C.Y.); (X.L.); (G.D.)
- University of Chinese Academy of Sciences, Beijing 100049, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Xiangcen Liu
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai 201210, China; (J.Z.); (J.S.); (C.Y.); (X.L.); (G.D.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guilin Du
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai 201210, China; (J.Z.); (J.S.); (C.Y.); (X.L.); (G.D.)
- University of Chinese Academy of Sciences, Beijing 100049, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Ruimei Fan
- Sino-UK Joint Laboratory for Brain Function and Injury and Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang 453003, China
- Correspondence: (R.F.); (B.Z.)
| | - Baoguo Zhang
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai 201210, China; (J.Z.); (J.S.); (C.Y.); (X.L.); (G.D.)
- University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (R.F.); (B.Z.)
| |
Collapse
|
6
|
Takeuchi T, Lin YT, Fekaris N, Umen J, Sears BB, Benning C. Modulation of CHT7 Complexes during Light/Dark- and Nitrogen-Mediated Life Cycle Transitions of Chlamydomonas. PLANT PHYSIOLOGY 2020; 184:1762-1774. [PMID: 33004613 PMCID: PMC7723089 DOI: 10.1104/pp.20.00864] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/21/2020] [Indexed: 06/11/2023]
Abstract
The Chlamydomonas reinhardtii Compromised Hydrolysis of Triacylglycerols7 (CHT7) protein has been previously implicated in the regulation of DNA metabolism and cell-cycle-related gene expression during nitrogen (N) deprivation, and its predicted protein interaction domains are necessary for function. Here, we examined impacts of the cht7 mutation during the cell division cycle under nutrient deficiency in light-dark synchronized cultures. We explored the potential mechanisms affecting CHT7 complex activities during the cell cycle and N starvation, with a focus on the possible interaction between CHT7 and the C. reinhardtii retinoblastoma tumor suppressor (RB) protein homolog MAT3. Notably, the absence of CHT7 did not negatively impact the synchrony of cell division and cell cycle progression during diel growth. Although the majority of CHT7 and MAT3/RB proteins were observed in separate complexes by blue native-PAGE, the two proteins coimmunoprecipitated both during synchronized growth and following N deprivation, suggesting the presence of low abundance subcomplexes containing CHT7 and MAT3/RB. Furthermore, we observed several phosphorylated isoforms of CHT7 under these conditions. To test the potential role of phosphorylation on the structure and function of CHT7, we performed site-directed mutagenesis of previously identified phosphorylated amino acids within CHT7. These phosphorylated residues were dispensable for CHT7 function, but phosphorylated variants of CHT7 persisted, indicating that yet-unidentified residues within CHT7 are also likely phosphorylated. Based on the interaction of CHT7 and MAT3/RB, we postulate the presence of a low-abundance or transient regulatory complex in C. reinhardtii that may be similar to DREAM-like complexes in other organisms.
Collapse
Affiliation(s)
- Tomomi Takeuchi
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Yang-Tsung Lin
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Nicholas Fekaris
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - James Umen
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Barbara B Sears
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Christoph Benning
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| |
Collapse
|
7
|
Cai Y. When to Sleep? CHT7 Is Critical for Nutrient-Dependent Quiescence in Chlamydomonas. THE PLANT CELL 2020; 32:810-811. [PMID: 32024688 PMCID: PMC7145501 DOI: 10.1105/tpc.20.00069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- Yingqi Cai
- Biology DepartmentBrookhaven National LaboratoryUpton, New York
| |
Collapse
|