51
|
Han X, Shi Y, Liu G, Guo Y, Yang Y. Activation of ROP6 GTPase by Phosphatidylglycerol in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2018; 9:347. [PMID: 29599797 PMCID: PMC5862815 DOI: 10.3389/fpls.2018.00347] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 03/01/2018] [Indexed: 05/05/2023]
Abstract
Plant Rho-like GTPases (ROPs) are switch-like proteins which play essential roles in controlling cell polarity development and cellular activities. ROPs are regulated by many factors, such as auxin, light, and RopGEFs and RopGAPs proteins. However, it has not been reported yet whether small molecules play a role in the regulation of ROP activity. Here, we showed that AtROP6 specially bound to a phospholipid, phosphatidylglycerol (PG), by the protein-lipid overlay and liposome sedimentation assays, and further MST assay gave a dissociation constant (Kd) of 4.8 ± 0.4 μM for binding of PG to His-AtROP6. PG profile analysis in Arabidopsis revealed that PG existed both in leaves and roots but with distinctive fatty acyl chain patterns. By evaluating AtROP6 activity using RIC1 effector binding-based assay, we found that PG stimulated AtROP6 activity. In the FM4-64 uptake experiment, PG inhibited AtROP6-mediated endocytosis process. By evaluating internalization of PIN2, PG was shown to regulate endocytosis process coordinately with NAA. Further root gravitropism experiment revealed that PG enhanced the AtROP6-mediated root gravity response. These results suggest that the phospholipid PG physically binds AtROP6, stimulates its activity and influences AtROP6-mediated root gravity response in Arabidopsis.
Collapse
|
52
|
Oda Y. Emerging roles of cortical microtubule-membrane interactions. JOURNAL OF PLANT RESEARCH 2018; 131:5-14. [PMID: 29170834 DOI: 10.1007/s10265-017-0995-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 10/25/2017] [Indexed: 05/04/2023]
Abstract
Plant cortical microtubules have crucial roles in cell wall development. Cortical microtubules are tightly anchored to the plasma membrane in a highly ordered array, which directs the deposition of cellulose microfibrils by guiding the movement of the cellulose synthase complex. Cortical microtubules also interact with several endomembrane systems to regulate cell wall development and other cellular events. Recent studies have identified new factors that mediate interactions between cortical microtubules and endomembrane systems including the plasma membrane, endosome, exocytic vesicles, and endoplasmic reticulum. These studies revealed that cortical microtubule-membrane interactions are highly dynamic, with specialized roles in developmental and environmental signaling pathways. A recent reconstructive study identified a novel function of the cortical microtubule-plasma membrane interaction, which acts as a lateral fence that defines plasma membrane domains. This review summarizes recent advances in our understanding of the mechanisms and functions of cortical microtubule-membrane interactions.
Collapse
Affiliation(s)
- Yoshihisa Oda
- Center for Frontier Research, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.
- Department of Genetics, SOKENDAI (The Graduate University for Advanced Studies), 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.
| |
Collapse
|
53
|
Kosetsu K, Murata T, Yamada M, Nishina M, Boruc J, Hasebe M, Van Damme D, Goshima G. Cytoplasmic MTOCs control spindle orientation for asymmetric cell division in plants. Proc Natl Acad Sci U S A 2017; 114:E8847-E8854. [PMID: 28973935 PMCID: PMC5651782 DOI: 10.1073/pnas.1713925114] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Proper orientation of the cell division axis is critical for asymmetric cell divisions that underpin cell differentiation. In animals, centrosomes are the dominant microtubule organizing centers (MTOC) and play a pivotal role in axis determination by orienting the mitotic spindle. In land plants that lack centrosomes, a critical role of a microtubular ring structure, the preprophase band (PPB), has been observed in this process; the PPB is required for orienting (before prophase) and guiding (in telophase) the mitotic apparatus. However, plants must possess additional mechanisms to control the division axis, as certain cell types or mutants do not form PPBs. Here, using live imaging of the gametophore of the moss Physcomitrella patens, we identified acentrosomal MTOCs, which we termed "gametosomes," appearing de novo and transiently in the prophase cytoplasm independent of PPB formation. We show that gametosomes are dispensable for spindle formation but required for metaphase spindle orientation. In some cells, gametosomes appeared reminiscent of the bipolar MT "polar cap" structure that forms transiently around the prophase nucleus in angiosperms. Specific disruption of the polar caps in tobacco cells misoriented the metaphase spindles and frequently altered the final division plane, indicating that they are functionally analogous to the gametosomes. These results suggest a broad use of transient MTOC structures as the spindle orientation machinery in plants, compensating for the evolutionary loss of centrosomes, to secure the initial orientation of the spindle in a spatial window that allows subsequent fine-tuning of the division plane axis by the guidance machinery.
Collapse
Affiliation(s)
- Ken Kosetsu
- Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Takashi Murata
- Division of Evolutionary Biology, National Institute for Basic Biology, Myodaiji-cho, Okazaki 444-8585, Japan
- Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Myodaiji-cho, Okazaki 444-8585, Japan
| | - Moé Yamada
- Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
| | - Momoko Nishina
- Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
| | - Joanna Boruc
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Mitsuyasu Hasebe
- Division of Evolutionary Biology, National Institute for Basic Biology, Myodaiji-cho, Okazaki 444-8585, Japan
- Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Myodaiji-cho, Okazaki 444-8585, Japan
| | - Daniël Van Damme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium;
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Gohta Goshima
- Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan;
| |
Collapse
|
54
|
Plant Cytokinesis: Terminology for Structures and Processes. Trends Cell Biol 2017; 27:885-894. [PMID: 28943203 DOI: 10.1016/j.tcb.2017.08.008] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 08/21/2017] [Accepted: 08/22/2017] [Indexed: 11/22/2022]
Abstract
Plant cytokinesis is orchestrated by a specialized structure, the phragmoplast. The phragmoplast first occurred in representatives of Charophyte algae and then became the main division apparatus in land plants. Major cellular activities, including cytoskeletal dynamics, vesicle trafficking, membrane assembly, and cell wall biosynthesis, cooperate in the phragmoplast under the guidance of a complex signaling network. Furthermore, the phragmoplast combines plant-specific features with the conserved cytokinetic processes of animals, fungi, and protists. As such, the phragmoplast represents a useful system for understanding both plant cell dynamics and the evolution of cytokinesis. We recognize that future research and knowledge transfer into other fields would benefit from standardized terminology. Here, we propose such a lexicon of terminology for specific structures and processes associated with plant cytokinesis.
Collapse
|