Yueh Cho
@ipmb.sinica.edu.tw
IPMB, Academia Sinica
RESEARCH, TEACHING, or OTHER INTERESTS
Plant Science, General Biochemistry, Genetics and Molecular Biology, Cell Biology, Physiology
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Kazue Kanehara, Yueh Cho, and Chao-Yuan Yu
Oxford University Press (OUP)
Abstract Organisms, including humans, seem to be constantly exposed to various changes, which often have undesirable effects, referred to as stress. To keep up with these changes, eukaryotic cells may have evolved a number of relevant cellular processes, such as the endoplasmic reticulum (ER) stress response. Owing to presumably intimate links between human diseases and the ER function, the ER stress response has been extensively investigated in various organisms for a few decades. Based on these studies, we now have a picture of the molecular mechanisms of the ER stress response, one of which, the unfolded protein response (UPR), is highly conserved among yeasts, mammals, higher plants, and green algae. In this review, we attempt to highlight the plant UPR from the perspective of lipids, especially membrane phospholipids. Phosphatidylcholine (PtdCho) and phosphatidylethanolamine (PtdEtn) are the most abundant membrane phospholipids in eukaryotic cells. The ratio of PtdCho to PtdEtn and the unsaturation of fatty acyl tails in both phospholipids may be critical factors for the UPR, but the pathways responsible for PtdCho and PtdEtn biosynthesis are distinct in animals and plants. We discuss the plant UPR in comparison with the system in yeasts and animals in the context of membrane phospholipids.
Chao-Yuan Yu, Yueh Cho, Oshin Sharma, and Kazue Kanehara
Oxford University Press (OUP)
Abstract The investigation of a phenomenon called the unfolded protein response (UPR) started approximately three decades ago, and we now know that the UPR is involved in a number of cellular events among metazoans, higher plants, and algae. The relevance of the UPR in human diseases featuring protein folding defects, such as Alzheimer’s and Huntington’s diseases, has drawn much attention to the response in medical research to date. While metazoans and plants share similar molecular mechanisms of the UPR, recent studies shed light on the uniqueness of the plant UPR, with plant-specific protein families appearing to play pivotal roles. Given the considerable emphasis on the original discoveries of key factors in metazoans, this review highlights the uniqueness of the plant UPR based on current knowledge.
Chen-Yuan Tseng, Yu-Han Su, Shun-Min Yang, Kun-Yang Lin, Chun-Ming Lai, Elham Rastegari, Oyundari Amartuvshin, Yueh Cho, Yu Cai, and Hwei-Jan Hsu
Elsevier BV
Yueh Cho, Chun-Ming Lai, Kun-Yang Lin, and Hwei-Jan Hsu
Oxford University Press (OUP)
AbstractAdult stem cells maintain tissue homeostasis. This unique capability largely depends on the stem cell niche, a specialized microenvironment, which preserves stem cell identity through physical contacts and secreted factors. In many cancers, latent tumor cell niches are thought to house stem cells and aid tumor initiation. However, in developing tissue and cancer it is unclear how the niche is established. The well-characterized germline stem cells (GSCs) and niches in the Drosophila melanogaster ovary provide an excellent model to address this fundamental issue. As such, we conducted a small-scale RNAi screen of 560 individually expressed UAS-RNAi lines with targets implicated in female fertility. RNAi was expressed in the soma of larval gonads, and screening for reduced egg production and abnormal ovarian morphology was performed in adults. Twenty candidates that affect ovarian development were identified and subsequently knocked down in the soma only during niche formation. Feminization factors (Transformer, Sex lethal, and Virilizer), a histone methyltransferase (Enhancer of Zeste), a transcriptional machinery component (Enhancer of yellow 1), a chromatin remodeling complex member (Enhancer of yellow 3) and a chromosome passenger complex constituent (Incenp) were identified as potentially functioning in the control of niche size. The identification of these molecules highlights specific molecular events that are critical for niche formation and will provide a basis for future studies to fully understand the mechanisms of GSC recruitment and maintenance.
Kuan-Ju Lu, Florence R. Danila, Yueh Cho, and Christine Faulkner
Wiley
Plasmodesmata (PD) are membrane-lined pores that connect neighbouring plant cells and allow molecular exchange via the symplast. Past studies have revealed the basic structure of PD, some of the transport mechanisms for molecules through PD, and a variety of physiological processes in which they function. Recently, with the help of newly developed technologies, several exciting new features of PD have been revealed. New PD structures were observed during early formation of PD and between phloem sieve elements and phloem pole pericycle cells in roots. Both observations challenge our current understanding of PD structure and function. Research into novel physiological responses, which are regulated by PD, indicates that we have not yet fully explored the potential contribution of PD to overall plant function. In this Viewpoint article, we summarize some of the recent advances in understanding the structure and function of PD and propose the challenges ahead for the community.
Yueh Cho, Chao-Yuan Yu, Yuki Nakamura, and Kazue Kanehara
Oxford University Press (OUP)
The early flowering phenotype of dok1 mutants and localization of DOK1 at meristems suggests the potential importance of dolichol kinase function in flowering time control.
Yueh Cho and Kazue Kanehara
Frontiers Media SA
Roots are the frontier of plant body to perceive underground environmental change. Endoplasmic reticulum (ER) stress response represents circumvention of cellular stress caused by various environmental changes; however, a limited number of studies are available on the ER stress responses in roots. Here, we report the tunicamycin (TM) -induced ER stress response in Arabidopsis roots by monitoring expression patterns of immunoglobulin-binding protein 3 (BiP3), a representative marker for the response. Roots promptly responded to the TM-induced ER stress through the induction of similar sets of ER stress-responsive genes. However, not all cells responded uniformly to the TM-induced ER stress in roots, as BiP3 was highly expressed in root tips, an outer layer in elongation zone, and an inner layer in mature zone of roots. We suggest that ER stress response in roots has tissue specificity.
Chen-Yuan Tseng, Shih-Han Kao, Chih-Ling Wan, Yueh Cho, Shu-Yun Tung, and Hwei-Jan Hsu
Public Library of Science (PLoS)
Copyright: © 2015 Tseng et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Yueh Cho, Chao-Yuan Yu, Tatsuo Iwasa, and Kazue Kanehara
Informa UK Limited
Canonical heterotrimeric G proteins in eukaryotes are major components that localize at plasma membrane and transmit extracellular stimuli into the cell. Genome of a seed plant Arabidopsis thaliana encodes at least one Gα (GPA1), one Gβ (AGB1), and 3 Gγ (AGG1, AGG2 and AGG3) subunits. The loss-of-function mutations of G protein subunit(s) cause multiple defects in development as well as biotic and abiotic stress responses. However, it remains elusive how these subunits differentially express these defects. Here, we report that Arabidopsis heterotrimeric G protein subunits differentially respond to the endoplasmic reticulum (ER) stress. An isolated homozygous mutant of AGB1, agb1-3, was more sensitive to the tunicamycin-induced ER stress compared to the wild type and the other loss-of-function mutants of G protein subunits. Moreover, ER stress responsive genes were highly expressed in the agb1-3 plant. Our results indicate that AGB1 positively contributes to ER stress tolerance in Arabidopsis.
Kazue Kanehara, Chao-Yuan Yu, Yueh Cho, Wei-Fun Cheong, Federico Torta, Guanghou Shui, Markus R Wenk, and Yuki Nakamura
Public Library of Science (PLoS)
Abstract Phosphoinositides represent important lipid signals in the plant development and stress response. However, multiple isoforms of the phosphoinositide biosynthetic genes hamper our understanding of the pivotal enzymes in each step of the pathway as well as their roles in plant growth and development. Here, we report that phosphoinositide-specific phospholipase C2 (AtPLC2) is the primary phospholipase in phosphoinositide metabolism and is involved in seedling growth and the endoplasmic reticulum (ER) stress responses in Arabidopsis thaliana. Lipidomic profiling of multiple plc mutants showed that the plc2-1 mutant increased levels of its substrates phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate, suggesting that the major phosphoinositide metabolic pathway is impaired. AtPLC2 displayed a distinct tissue expression pattern and localized at the plasma membrane in different cell types, where phosphoinositide signaling occurs. The seedlings of plc2-1 mutant showed growth defect that was complemented by heterologous expression of AtPLC2, suggesting that phosphoinositide-specific phospholipase C activity borne by AtPLC2 is required for seedling growth. Moreover, the plc2-1 mutant showed hypersensitive response to ER stress as evidenced by changes in relevant phenotypes and gene expression profiles. Our results revealed the primary enzyme in phosphoinositide metabolism, its involvement in seedling growth and an emerging link between phosphoinositide and the ER stress response.
Kazue Kanehara, Yueh Cho, Ying-Chen Lin, Chia-En Chen, Chao-Yuan Yu, and Yuki Nakamura
Wiley
Dolichol phosphate (Dol-P) serves as a carrier of complex polysaccharides during protein glycosylation. Dol-P is synthesized by the phosphorylation of dolichol or the monodephosphorylation of dolichol pyrophosphate (Dol-PP); however, the enzymes that catalyze these reactions remain unidentified in Arabidopsis thaliana. We performed a genome-wide search for cytidylyltransferase motif-containing proteins in Arabidopsis, and found that At3g45040 encodes a protein homologous with Sec59p, a dolichol kinase (DOK) in Saccharomyces cerevisiae. At3g45040, designated AtDOK1, complemented defects in the growth and N-linked glycosylation of the S. cerevisiae sec59 mutant, suggesting that AtDOK1 encodes a functional DOK. To characterize the physiological roles of AtDOK1 in planta, we isolated two independent lines of T-DNA-tagged AtDOK1 mutants, dok1-1 and dok1-2. The heterozygous plants showed developmental defects in male and female gametophytes, including an aberrant pollen structure, low pollen viability, and short siliques. Additionally, the mutations had incomplete penetrance. These results suggest that AtDOK1 is a functional DOK required for reproductive processes in Arabidopsis.
Chen-Yuan Tseng, Shih-Han Kao, Chih-Ling Wan, Yueh Cho, Shu-Yun Tung, and Hwei-Jan Hsu
Public Library of Science (PLoS)
Stem cells have an innate ability to occupy their stem cell niche, which in turn, is optimized to house stem cells. Organ aging is associated with reduced stem cell occupancy in the niche, but the mechanisms involved are poorly understood. Here, we report that Notch signaling is increased with age in Drosophila female germline stem cells (GSCs), and this results in their removal from the niche. Clonal analysis revealed that GSCs with low levels of Notch signaling exhibit increased adhesiveness to the niche, thereby out-competing their neighbors with higher levels of Notch; adhesiveness is altered through regulation of E-cadherin expression. Experimental enhancement of Notch signaling in GSCs hastens their age-dependent loss from the niche, and such loss is at least partially mediated by Sex lethal. However, disruption of Notch signaling in GSCs does not delay GSC loss during aging, and nor does it affect BMP signaling, which promotes self-renewal of GSCs. Finally, we show that in contrast to GSCs, Notch activation in the niche (which maintains niche integrity, and thus mediates GSC retention) is reduced with age, indicating that Notch signaling regulates GSC niche occupancy both intrinsically and extrinsically. Our findings expose a novel role of Notch signaling in controlling GSC-niche adhesion in response to aging, and are also of relevance to metastatic cancer cells, in which Notch signaling suppresses cell adhesion.