Identification of a homeobox-containing gene located between lin-45 and unc-24 on chromosome IV in the nematode Caenorhabditis elegans.
Ontology highlight
ABSTRACT:
SUBMITTER: Naito M
PROVIDER: S-EPMC312424 | biostudies-other | 1992 Jun
REPOSITORIES: biostudies-other
Publications
Identification of a homeobox-containing gene located between lin-45 and unc-24 on chromosome IV in the nematode Caenorhabditis elegans.
Naito M M Kohara Y Y Kurosawa Y Y
Nucleic acids research 19920601 12
Using two primers corresponding to helix 1 and helix 3 regions in the homeodomain, we subjected genomic DNA from Caenorhabditis elegans to amplification by the polymerase chain reaction. Sequence analysis of the amplified products revealed a new homeobox-containing gene, designated ceh-19. This gene was located between lin-45 and unc-24 on chromosome IV where no homeogene has previously been mapped. ...[more]
Similar Datasets
Project description:We designed a unique 36-mer oligonucleotide probe, based on the most highly conserved amino acid sequences of Antennapedia-like homeodomains and the codon bias of Caenorhabditis elegans. This probe was then used to isolate four classes of genes from a C. elegans genomic library. Sequencing reveals that we have isolated three new homeobox genes, designated ceh-1, ceh-9 and ceh-10. The fourth homeobox gene, ceh-11, has recently been described by Schaller et al (Nucleic Acids Res. 18, 2033-2036). The amino acid sequence of ceh-1 is 87% similar to the honeybee H40 homeodomain, 85% similar to the Drosophila NK-1 homeodomain and 82% similar to the chicken CHox3 homeodomain. The sequence ceh-10 appears to be a member of the paired class of homeodomains. The other two sequences, ceh-9 and ceh-11, remain unclassified. Three of the four sequences have at least one intron within the homeobox region. Transcripts of ceh-10 and ceh-11 are present in embryonic RNA but are greatly diminished in later developmental stages. Three of the four new genes have been placed on the C. elegans genomic map.
| S-EPMC332412 | biostudies-other
Project description:Myosin motors are central to diverse cellular processes in eukaryotes. Homologues of the myosin chaperone UNC-45 have been implicated in the assembly and function of myosin-containing structures in organisms from fungi to humans. In muscle, the assembly of sarcomeric myosin is regulated to produce stable, uniform thick filaments. Loss-of-function mutations in Caenorhabditis elegans UNC-45 lead to decreased muscle myosin accumulation and defective thick filament assembly, resulting in paralyzed animals. We report that transgenic worms overexpressing UNC-45 also display defects in myosin assembly, with decreased myosin content and a mild paralysis phenotype. We find that the reduced myosin accumulation is the result of degradation through the ubiquitin/proteasome system. Partial proteasome inhibition is able to restore myosin protein and worm motility to nearly wild-type levels. These findings suggest a mechanism in which UNC-45-related proteins may contribute to the degradation of myosin in conditions such as heart failure and muscle wasting.
| S-EPMC2064129 | biostudies-literature
Project description:The Caenorhabditis elegans unc-45 locus has been proposed to encode a protein machine for myosin assembly. The UNC-45 protein is predicted to contain an NH2-terminal domain with three tetratricopeptide repeat motifs, a unique central region, and a COOH-terminal domain homologous to CRO1 and She4p. CRO1 and She4p are fungal proteins required for the segregation of other molecules in budding, endocytosis, and septation. Three mutations that lead to temperature-sensitive (ts) alleles have been localized to conserved residues within the CRO1/She4p-like domain, and two lethal alleles were found to result from stop codon mutations in the central region that would prevent translation of the COOH-terminal domain. Electron microscopy shows that thick filament accumulation in vivo is decreased by approximately 50% in the CB286 ts mutant grown at the restrictive temperature. The thick filaments that assemble have abnormal structure. Immunofluorescence and immunoelectron microscopy show that myosins A and B are scrambled, in contrast to their assembly into distinct regions at the permissive temperature and in wild type. This abnormal structure correlates with the high degree of instability of the filaments in vitro as reflected by their extremely low yields and shortened lengths upon isolation. These results implicate the UNC-45 CRO1/She4p-like region in the assembly of myosin isoforms in C. elegans and suggest a possible common mechanism for the function of this UCS (UNC-45/CRO1/She4p) protein family.
| S-EPMC2133068 | biostudies-literature
Project description:Three homeobox-containing genes from the nematode Caenorhabditis elegans are described. Two of them (ceh-11 and ceh-12) were isolated from a genomic library by hybridization at low stringency with the Ascaris lumbricoides homeobox AHB-1. The first clone contains a homeobox defining a new class of homeoboxes (ceh-11). This gene maps on the third chromosome of C. elegans, at the same locus as egl-5, a gene already known to be essential for the determination of specific neurons. In the second clone, sequence analysis revealed the existence of the third helix of a putative homeobox (ceh-12) which is interrupted by an intron located upstream of the codon for the amino acid 45 of the homeodomain. Using the ceh-11 homeobox as a probe, a third homeobox (ceh-13) was isolated from a cDNA library. As ceh-13 belongs to the labial class of homeoboxes, we conclude that, at the time when the nematode lineage diverged from the myriapod-insect and the vertebrate lineages, the duplication which led to the Antp and the labial families of homeoboxes had already taken place.
| S-EPMC330679 | biostudies-other
Project description:Durotaxis is a process where cells are able to sense the stiffness of substrates and preferentially migrate toward stiffer regions. Here, we show that the 1-mm-long nematode, Caenorhabditis elegans are also able to detect the rigidity of underlying substrates and always migrate to regions of higher stiffness. Our results indicate that C. elegans are able to judiciously make a decision to stay on stiffer regions. We found that the, undulation frequency, and wavelength of worms, crawling on surfaces show nonmonotonic behavior with increasing stiffness. A number of control experiments were also conducted to verify whether C. elegans are really able to detect the rigidity of substrates or whether the migration to stiffer regions is due to other factors already reported in the literature. As it is known that bacteria and other single-celled organisms exhibit durotaxis toward stiffer surfaces, we conjecture that durotaxis in C. elegans may be one of the strategies developed to improve their chances of locating food.
| S-EPMC4982933 | biostudies-literature
Project description:Acute ethanol exposure affects the nervous system as a stimulant at low concentrations and as a depressant at higher concentrations, eventually resulting in motor dysfunction and uncoordination. A recent genetic study of two mouse strains with varying ethanol preference indicated a correlation with a polymorphism (D216N) in the synaptic protein Munc18-1. Munc18-1 functions in exocytosis via a number of discrete interactions with the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein syntaxin-1. We report that the mutation affects binding to syntaxin but not through either a closed conformation mode of interaction or through binding to the syntaxin N terminus. The D216N mutant instead has a specific impairment in binding the assembled SNARE complex. Furthermore, the mutation broadens the duration of single exocytotic events. Expression of the orthologous mutation (D214N) in the Caenorhabditis elegans UNC-18 null background generated transgenic rescues with phenotypically similar locomotion to worms rescued with the wild-type protein. Strikingly, D214N worms were strongly resistant to both stimulatory and sedative effects of acute ethanol. Analysis of an alternative Munc18-1 mutation (I133V) supported the link between reduced SNARE complex binding and ethanol resistance. We conclude that ethanol acts, at least partially, at the level of vesicle fusion and that its acute effects are ameliorated by point mutations in UNC-18.
| S-EPMC2613081 | biostudies-literature
Project description:unc-94 is one of about 40 genes in Caenorhabditis elegans that, when mutant, displays an abnormal muscle phenotype. Two mutant alleles of unc-94, su177 and sf20, show reduced motility and brood size and disorganization of muscle structure. In unc-94 mutants, immunofluorescence microscopy shows that a number of known sarcomeric proteins are abnormal, but the most dramatic effect is in the localization of F-actin, with some abnormally accumulated near muscle cell-to-cell boundaries. Electron microscopy shows that unc-94(sf20) mutants have large accumulations of thin filaments near the boundaries of adjacent muscle cells. Multiple lines of evidence prove that unc-94 encodes a tropomodulin, a conserved protein known from other systems to bind to both actin and tropomyosin at the pointed ends of actin thin filaments. su177 is a splice site mutation in intron 1, which is specific to one of the two unc-94 isoforms, isoform a; sf20 has a stop codon in exon 5, which is shared by both isoform a and isoform b. The use of promoter-green fluorescent protein constructs in transgenic animals revealed that unc-94a is expressed in body wall, vulval and uterine muscles, whereas unc-94b is expressed in pharyngeal, anal depressor, vulval and uterine muscles and in spermatheca and intestinal epithelial cells. By Western blot, anti-UNC-94 antibodies detect polypeptides of expected size from wild type, wild-type-sized proteins of reduced abundance from unc-94(su177), and no detectable unc-94 products from unc-94(sf20). Using these same antibodies, UNC-94 localizes as two closely spaced parallel lines flanking the M-lines, consistent with localization to the pointed ends of thin filaments. In addition, UNC-94 is localized near muscle cell-to-cell boundaries.
| S-EPMC2175264 | biostudies-literature
Project description:Two types of cell death have been studied extensively in Caenorhabditis elegans, programmed cell death and necrosis. We describe a novel type of cell death that occurs in animals containing mutations in either of two genes, lin-24 and lin-33. Gain-of-function mutations in lin-24 and lin-33 cause the inappropriate deaths of many of the Pn.p hypodermal blast cells and prevent the surviving Pn.p cells from expressing their normal developmental fates. The abnormal Pn.p cells in lin-24 and lin-33 mutant animals are morphologically distinct from the dying cells characteristic of C. elegans programmed cell deaths and necrotic cell deaths. lin-24 encodes a protein with homology to bacterial toxins. lin-33 encodes a novel protein. The cytotoxicity caused by mutation of either gene requires the function of the other. An evolutionarily conserved set of genes required for the efficient engulfment and removal of both apoptotic and necrotic cell corpses is required for the full cell-killing effect of mutant lin-24 and lin-33 genes, suggesting that engulfment promotes these cytotoxic cell deaths.
| S-EPMC2390618 | biostudies-literature
Project description:After endocytosis, membrane proteins are often sorted between two alternative pathways: a recycling pathway and a degradation pathway. Relatively little is known about how trafficking through these alternative pathways is differentially regulated. Here, we identify UNC-108/Rab2 as a regulator of postendocytic trafficking in both neurons and coelomocytes. Mutations in the Caenorhabditis elegans Rab2 gene unc-108, caused the green fluorescent protein (GFP)-tagged glutamate receptor GLR-1 (GLR-1::GFP) to accumulate in the ventral cord and in neuronal cell bodies. In neuronal cell bodies of unc-108/Rab2 mutants, GLR-1::GFP was found in tubulovesicular structures that colocalized with markers for early and recycling endosomes, including Syntaxin-13 and Rab8. GFP-tagged Syntaxin-13 also accumulated in the ventral cord of unc-108/Rab2 mutants. UNC-108/Rab2 was not required for ubiquitin-mediated sorting of GLR-1::GFP into the multivesicular body (MVB) degradation pathway. Mutations disrupting the MVB pathway and unc-108/Rab2 mutations had additive effects on GLR-1::GFP levels in the ventral cord. In coelomocytes, postendocytic trafficking of the marker Texas Red-bovine serum albumin was delayed. These results demonstrate that UNC-108/Rab2 regulates postendocytic trafficking, most likely at the level of early or recycling endosomes, and that UNC-108/Rab2 and the MVB pathway define alternative postendocytic trafficking mechanisms that operate in parallel. These results define a new function for Rab2 in protein trafficking.
| S-EPMC2441656 | biostudies-literature
Project description:Axons navigating through the developing nervous system are instructed by external attractive and repulsive cues. Emerging evidence suggests the same cues control dendrite development, but it is not understood how they differentially instruct axons and dendrites. We studied a C. elegans motor neuron whose axon and dendrite adopt different trajectories and lengths. We found that the guidance cue UNC-6 (Netrin) is required for both axon and dendrite development. Its repulsive receptor UNC-5 repelled the axon from the ventral cell body, whereas the attractive receptor UNC-40 (DCC) was dendritically enriched and promotes antero-posterior dendritic growth. Although the endogenous ventrally secreted UNC-6 instructs axon guidance, dorsal or even membrane-tethered UNC-6 could support dendrite development. Unexpectedly, the serine-threonine kinase PAR-4 (LKB1) was selectively required for the activity of the UNC-40 pathway in dendrite outgrowth. These data suggest that axon and dendrite of one neuron interpret common environmental cues with different receptors and downstream signaling pathways.
| S-EPMC3908881 | biostudies-literature