Publications by authors named "Yukimasa Shibata"

Article Synopsis
  • - Chondroitin has been found to extend both lifespan and healthspan in the model organism C. elegans, but how it interacts with anti-aging processes inside cells is not fully understood.
  • - The study reveals that chondroitin plays a crucial role in aging by promoting the formation of hemidesmosomes and preventing the excessive formation of tubular lysosomes that are linked to aging.
  • - A mutation in the gene that produces chondroitin leads to earlier aging signs, specifically through excessive tubular lysosome formation, while the VHA-7 protein helps mitigate the effects of such mutations, indicating a potential new anti-aging mechanism controlled by the extracellular matrix.
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The ADAMTS (a disintegrin and metalloprotease with thrombospondin motifs) family metalloprotease MIG-17 plays a crucial role in the migration of gonadal distal tip cells (DTCs) in Caenorhabditis elegans. MIG-17 is secreted from the body wall muscle cells and localizes to the basement membranes (BMs) of various tissues including the gonadal BM where it regulates DTC migration through its catalytic activity. Missense mutations in the BM protein genes, let-2/collagen IV a2 and fbl-1/fibulin-1, have been identified as suppressors of the gonadal defects observed in mig-17 mutants.

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Many repeat sequences in genomes have unknown functions, but some have features that are suggestive of one. I found a repeat sequence that has 185 base pairs as the basic unit, which is the same as the length of a nucleosome repeat. The chromosomal location of this repeat sequence is opposite the pairing center of each autosomal chromosome.

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Chondroitin, a class of glycosaminoglycan polysaccharides, is found as proteoglycans in the extracellular matrix, plays a crucial role in tissue morphogenesis during development and axonal regeneration. Ingestion of chondroitin prolongs the lifespan of C. elegans.

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  • The text indicates that there is a correction to be made regarding a previously published article related to the DOI 10.1371/journal.pone.0240571.
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Repulsive guidance molecules (RGMs) are evolutionarily conserved proteins implicated in repulsive axon guidance. Here we report the function of the Caenorhabditis elegans ortholog DRAG-1 in axon branching. The axons of hermaphrodite-specific neurons (HSNs) extend dorsal branches at the region abutting the vulval muscles.

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Article Synopsis
  • The development of Caenorhabditis elegans gonads involves distal tip cells (DTCs) migrating in a U-shape, and the correct migration of these cells relies on the metalloproteases MIG-17 and GON-1.
  • Mutations in mig-17 lead to abnormal gonad shapes due to misdirection, while gon-1 mutations cause swollen and shortened gonads due to early migration termination.
  • Some basement membrane protein mutations act as genetic suppressors for both mig-17 and gon-1 mutants, indicating that while these proteases have distinct functions, they also share roles in gonad formation, particularly in regulating collagen IV levels in the DTC basement membrane.
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Cell-fate maintenance is important to preserve the variety of cell types that are essential for the formation and function of tissues. We previously showed that the acetylated histone-binding protein BET-1 maintains cell fate by recruiting the histone variant H2A.z.

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MIG-17, a secreted protease of the ADAMTS family, acts in the directed migration of gonadal distal tip cells (DTCs) through regulation of the gonadal basement membrane in Caenorhabditis elegans Here, we show that MIG-17 is also required for the control of pharynx elongation during animal growth. We found that the pharynx was elongated in mig-17 mutants compared with wild type. MIG-17 localized to the pharyngeal basement membrane as well as to the gonadal basement membrane.

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Article Synopsis
  • Epithelial tubes play a crucial role in organ formation, and the termination of their growth is essential for proper organ size and shape, although the specific mechanisms remain largely unclear.
  • Research reveals that the protein MIG-39 is vital for stopping the migration of gonadal leader cells (DTCs) in Caenorhabditis elegans, as its absence leads to DTC overshooting their intended stopping point.
  • Genetic studies indicate that MIG-39 works alongside Rac GTPases to regulate DTC migration, with different responses observed in anterior and posterior DTCs based on the levels of Rac activity.
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Maintenance of cell fates is essential for the development and homeostasis of multicellular organisms and involves the preservation of the expression status of selector genes that control many target genes. Epigenetic marks have pivotal roles in the maintenance of gene expression status, as occurs with methylation on lysine 27 of histone H3 (H3K27me) for Hox gene regulation. In contrast, because the levels of histone acetylation decrease during the mitotic phase, acetylated histone has not been believed to contribute to the maintenance of cell fates.

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Histone H3K4 methylation has been linked to transcriptional activation. KDM5A (also known as RBP2 or JARID1A), a member of the KDM5 protein family, is an H3K4 demethylase, previously implicated in the regulation of transcription and differentiation. Here, we show that KDM5A is physically and functionally associated with two histone deacetylase complexes.

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The stable maintenance of acquired cell fates is important during development and for maintaining tissue homeostasis. Although histone modification is one of the major strategies used by cells to maintain their fates, the mechanisms by which histone variants maintain cell fates are not well understood. In C.

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The migration of Caenorhabditis elegans gonadal distal tip cells (DTCs) offers an excellent model to study the migration of epithelial tubes in organogenesis. mig-18 mutants cause meandering or wandering migration of DTCs during gonad formation, which is very similar to that observed in animals with mutations in mig-17, which encodes a secreted metalloprotease of the ADAMTS (a disintegrin and metalloprotease with thrombospondin motifs) family. MIG-18 is a novel secreted protein that is conserved only among nematode species.

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Article Synopsis
  • The SWI/SNF-like chromatin remodeling complexes have two main subclasses, identified by the presence of OSA/BAF250 and Polybromo proteins, which help regulate different sets of target genes during C. elegans development.
  • In a study, researchers discovered that the LET-526 and PBRM-1 proteins, which correspond to these subclasses, influence asymmetric cell division and have overlapping targets in T cell division but distinct roles in gonad development.
  • The findings suggest that while both proteins are crucial for certain processes, some genes can still be regulated independently of LET-526 or PBRM-1, highlighting the complex regulatory dynamics of chromatin remodeling in developmental biology.
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The maintenance of cell fate is important for normal development and tissue homeostasis. Epigenetic mechanisms, including histone modifications, are likely to play crucial roles in cell-fate maintenance. However, in contrast to the established functions of histone methylation, which are mediated by the polycomb proteins, the roles of histone acetylation in cell-fate maintenance are poorly understood.

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Semaphorins are extracellular proteins that regulate axon guidance and morphogenesis by interacting with a variety of cell surface receptors. Most semaphorins interact with plexin-containing receptor complexes, although some interact with non-plexin receptors. Class 2 semaphorins are secreted molecules that control axon guidance and epidermal morphogenesis in Drosophila and Caenorhabditis elegans.

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In vitro studies have indicated that reactive oxygen species (ROS) and the oxidation of signaling molecules are important mediators of signal transduction. We have identified two pathways by which the altered redox chemistry of the clk-1 mutants of Caenorhabditis elegans acts in vivo on germline development. One pathway depends on the oxidation of an analog of vertebrate low density lipoprotein (LDL) and acts on the germline through the Ack-related tyrosine kinase (ARK-1) kinase and inositol trisphosphate (IP3) signaling.

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The plexin family transmembrane proteins are putative receptors for semaphorins, which are implicated in the morphogenesis of animal embryos, including axonal guidance. We have generated and characterized putative null mutants of the C. elegans plexinA gene, plx-1.

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