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26 results on '"Tian, Qingnan"'

5. MRLC controls apoptotic cell death and functions to regulate epidermal development during planarian regeneration and homeostasis.

Author

Sun, Yujia, Huang, Yongding, Hao, Zhitai, Zhang, Shoutao, and Tian, Qingnan

Subjects
CELL physiology, CELL death, REGENERATION (Biology), KERATINOCYTE differentiation, HOMEOSTASIS, ANIMAL mortality
Abstract

Adult stem cells (ASCs) are pluripotent cells with the capacity to self‐renew and constantly replace lost cells due to physiological turnover or injury. Understanding the molecular mechanisms of the precise coordination of stem cell proliferation and proper cell fate decision is important to regeneration and organismal homeostasis. The planarian epidermis provides a highly tractable model to study ASC complex dynamic due to the distinct spatiotemporal differentiation stages during lineage development. Here, we identified the myosin regulatory light chain (MRLC) homologue in the Dugesia japonica transcriptome. We found high expression levels of MRLC in wound region during regeneration and also expressed in late epidermal progenitors as an essential regulator of the lineage from neoblasts to mature epidermal cells. We investigated the function of MRLC using in situ hybridization, real‐time polymerase chain reaction and double fluorescent and uncovered the potential mechanism. Knockdown of MRLC leads to a remarkable increase in cell death, causes severe abnormalities during regeneration and homeostasis and eventually leads to animal death. The global decrease in epidermal cell in MRLC RNAi animals induces accelerated epidermal proliferation and differentiation. Additionally, we find that MRLC is co‐expressed with cdc42 and acts cooperatively to control the epidermal lineage development by affecting cell death. Our results uncover an important role of MRLC, as an inhibitor of apoptosis, involves in epidermal development. [ABSTRACT FROM AUTHOR]

Published
2024
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10. Whole-genome sequence of the planarian Dugesia japonica combining Illumina and PacBio data

Author

Tian, Qingnan, Guo, Qi, Guo, Yanan, Luo, Longhai, Kristiansen, Karsten, Han, Zujing, Fang, Huimin, Zhang, Shoutao, Tian, Qingnan, Guo, Qi, Guo, Yanan, Luo, Longhai, Kristiansen, Karsten, Han, Zujing, Fang, Huimin, and Zhang, Shoutao

Abstract

Advances in stem cell biology have posed the challenges in revealing the mechanistic themes underlying whole tissues and organs formation during regeneration. The planarian Dugesia japonica is an ideal model organism for the study of regeneration and stem cell biology. However, the genome resources for this species are still limited. Here, we combined single-molecule real-time DNA sequencing platform Pacific Biosciences (PacBio) sequencing, Illumina paired-end sequencing and 10× Genomics linked reads data to obtain the whole-genome sequence of the planarian D. japonica. The final assembled D. japonica genome is 1.13G with contig N50 of 248.44 kb, and scaffold N50 of 652.52 kb. Repeat elements account for 64.92% of the genome, and 12,031 protein coding genes were annotated, of which 10,114 genes had at least one functional annotation, representing 84.07% of the total genes. We present a highly contiguous genome assembly of D. japonica. The D. japonica genome assembly, together with gene annotation and transcriptome data provide a valuable resource to investigate molecular mechanism of planarian and stem cell research.

Published
2022

23. TINP1homolog is required for planarian regeneration

Author

Sun, Yujia, Gao, Tingting, Zhang, Shoutao, Zhang, Yizhe, and Tian, Qingnan

Abstract

ABSTRACTThe planarian flatworm is an ideal system for the study of regeneration in vivo. In this study, we focus on TINP1, which is one of the most conserved proteins in eukaryotic organisms. We found that TINP1was expressed in parenchymal region through whole body as well as central nervous system (CNS) during the course of regeneration. RNA interference targeting DjTINP1caused lysis defects in regenerating tissues and a decreased in cell division and expression levels of DjpiwiAand Djpcna. Furthermore, the expression levels of DjTINP1were decreased when we inhibited the TGF-β signal by knockdown of smad4, which is the sole co-smad and has been proved to control the blastema patterning and central nervous system (CNS) regeneration in planarians. These findings suggest that DjTINP1participate in the maintenance of neoblasts and be required for proper cell proliferation in planarians as a downstream gene of the TGF-β signal pathway.

Published
2019
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26. SerRS-tRNASec complex structures reveal mechanism of the first step in selenocysteine biosynthesis.

Author

Wang C, Guo Y, Tian Q, Jia Q, Gao Y, Zhang Q, Zhou C, and Xie W

Subjects
Humans, Models, Molecular, Nucleic Acid Conformation, Protein Binding, Protein Structure, Tertiary, RNA, Transfer, Amino Acid-Specific metabolism, Serine-tRNA Ligase metabolism, Substrate Specificity, RNA, Transfer, Amino Acid-Specific chemistry, Selenocysteine biosynthesis, Serine-tRNA Ligase chemistry
Abstract

Selenocysteine (Sec) is found in the catalytic centers of many selenoproteins and plays important roles in living organisms. Malfunctions of selenoproteins lead to various human disorders including cancer. Known as the 21st amino acid, the biosynthesis of Sec involves unusual pathways consisting of several stages. While the later stages of the pathways are well elucidated, the molecular basis of the first stage-the serylation of Sec-specific tRNA (tRNA(Sec)) catalyzed by seryl-tRNA synthetase (SerRS)-is unclear. Here we present two cocrystal structures of human SerRS bound with tRNA(Sec) in different stoichiometry and confirm the formation of both complexes in solution by various characterization techniques. We discovered that the enzyme mainly recognizes the backbone of the long variable arm of tRNA(Sec) with few base-specific contacts. The N-terminal coiled-coil region works like a long-range lever to precisely direct tRNA 3' end to the other protein subunit for aminoacylation in a conformation-dependent manner. Restraints of the flexibility of the coiled-coil greatly reduce serylation efficiencies. Lastly, modeling studies suggest that the local differences present in the D- and T-regions as well as the characteristic U20:G19:C56 base triple in tRNA(Sec) may allow SerRS to distinguish tRNA(Sec) from closely related tRNA(Ser) substrate., (© The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Published
2015
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