Lobel L et al. (1993) Worm Breeder's Gazette "Mapping the Alpha1 and Beta Subunits of the C. elegans Voltage-Gated CalciumChannel"

Glossmann H, Lobel L, Horvitz HR, Grabner M

[Worm Breeder's Gazette, 1993]

We recently reported (1993 C. elegans meeting) the cloning of unc-36 ,a gene that encodes a protein similar to the alpha2 subunit of the voltage-gated calcium channel from mammals. Since then we isolated DNA clones by PCR encoding homologous sequences to portions of the alpha1 and beta subunits of the calcium channel. The alpha1 clone is 1 kb in length and has 52% identity and 74% similarity to a rodent alpha1 subunit. The beta clone is only 250 bp in size and has 68% identity and 76% similarity to a human beta clone. We have used these clones to probe the YAC polytene filters (provided by Alan Coulson). Our results indicate that there are at least two loci encoding an alpha1 homologous peptide, and at least five loci encoding beta homologous peptides. Our results are summarized below. There are at least two loci encoding alpha1 subunits: a) LGIV near eat-12 /egl-19 .Positive YACs Y51C8 and Y49F12 .Positive cosmids C11E10 ,K11C12 ,B0496 ,and C48A7 .b) LGII between fer-15 and rol-6 .Positive YAC Y24H1 . There are at least five loci encoding beta subunits: a) LGI near ces-2 .Positive YACs Y62C9 and Y65E10 .b) LGIV near let-280 ,let-281 ,let-282 ,let284 .Positive YACs Y53H3 and Y38A7 .c) LGV near ric-4 .Positive YACs Y47H11 ,Y22G9 and Y54B9 .Positive cosmid C14H1 .d) LGX near vit-3 ,vit-4 .Positive YAC Y60B6 .e) LGX between unc-6 and dpy-7 .Positive YACs Y51D11 and Y53D9 . The identification of multiple loci encoding alpha1 and beta homologous peptides agrees well with the variety of voltage-gated calcium channels being isolated from mammals. It has been demonstrated, for example by Campbell's laboratory (ref. 1 and personal communication), that the physiological classification of voltage-gated calcium channels (i.e. L and N) corresponds to slight antigenic variation between the subunits of these channel types. Our identification of multiple alpha1 and beta subunit loci may be a manifestation of the variety of voltage-gated channels in C. elegans. We plan to screen a cDNA library with these clones and use the cDNAs to produce subunit specific antibodies. We are also testing previously isolated mutants that map near the above loci for defects in these calcium channel subunits. l) Witcher D., De-Waard M., Sakamoto J., Franzini-Armstrong C., Pragnell M., Kahl S.D., Campbell K.P. Science, 261, 486,1993.

Rybicka K et al. (2000) East Coast Worm Meeting "MUP-4 is a novel matrix receptor with essential functions in epithelial cell adhesion, morphogenesis and maintenance of muscle position."

Bucher EA, Ward J, Hong L, Franzini-Armstrong C, Rybicka K, Elbl T

[East Coast Worm Meeting, 2000]

mup-4 is essential for maintenance of muscle position and for epithelial (hypodermal) cell organization during C. elegans embryonic development (Gatewood, B.K. and Bucher, E.A. Genetics. 146:165-183). We now report that MUP-4 is a large transmembrane protein comprised of an extracellular domain with twenty-eight EGF-like repeats, a single von Willebrand Factor A module and two SEA modules. The intracellular domain has homology to a class of intermediate filament (IF) associated proteins, the filaggrins, which are known to regulate IF compaction in vertebrate epithelium, but which have not previously been identified as a component of junctional complexes. MUP-4 colocalizes with IF structures, consistent with a possible role in IF regulation and/or association in response to extracellular signals. Ultrastructural studies demonstrate a lesion in mup-4 mutants at the apical, cuticular surface of the hypodermal epithelium. We propose that MUP-4 functions as an ECM receptor that regulates and maintains hemidesmosome-like structures, some of which function to transduce muscle force to the exoskeletal cuticle. Additional expression and phenotypic data support other roles for this novel matrix receptor in postembryonic muscle development and in epithelial morphogenesis.

Rybicka K et al. (2000) Midwest Worm Meeting "MUP-4 is a novel matrix receptor with essential functions in epithelial cell adhesion, morphogenesis and maintenance of muscle position."

Ward J, Franzini-Armstrong C, Elbl T, Rybicka K, Bucher EA, Hong L

[Midwest Worm Meeting, 2000]

mup-4 is essential for maintenance of muscle position and for epithelial (hypodermal) cell organization during C. elegans embryonic development (Gatewood, B.K. and Bucher, E.A. Genetics. 146:165-183). We now report that MUP-4 is a large transmembrane protein comprised of an extracellular domain with twenty-eight EGF-like repeats, a single von Willebrand Factor A module and two SEA modules. The intracellular domain has homology to a class of intermediate filament (IF) associated proteins, the filaggrins, which are known to regulate IF compaction in vertebrate epithelium, but which have not previously been identified as a component of junctional complexes. MUP-4 colocalizes with IF structures, consistent with a possible role in IF regulation and/or association in response to extracellular signals. Ultrastructural studies demonstrate a lesion in mup-4 mutants at the apical, cuticular surface of the hypodermal epithelium. We propose that MUP-4 functions as an ECM receptor that regulates and maintains hemidesmosome-like structures, some of which function to transduce muscle force to the exoskeletal cuticle. Additional expression and phenotypic data support other roles for this novel matrix receptor in postembryonic muscle development and in epithelial morphogenesis.

Burkeen AK et al. (2004) Biophys J "Disruption of Caenorhabditis elegans muscle structure and function caused by mutation of troponin I."

Franzini-Armstrong C, Barstead R, Rybicka KK, Sulcove JA, Ward J, Burkeen AK, Maday SL, Huang MM, Allen TStC

[Biophys J, 2004]

Caenorhabditis elegans strains mutant for the unc-27 gene show abnormal locomotion and muscle structure. Experiments revealed that unc-27 is one of four C. elegans troponin I genes and that three mutant alleles truncate the protein: recessive and presumed null allele e155 terminates after nine codons; semidominant su142sd eliminates the inhibitory and C-terminal regions; and semidominant su195sd abbreviates the extreme C-terminus. Assays of in vivo muscular performance at high and low loads indicated that su142sd is most deleterious, with e155 least and su195sd intermediate. Microscopy revealed in mutant muscle a prevalent disorder of dense body positioning and a less well defined sarcomeric structure, with small islands of thin. laments interspersed within the overlap region of A bands and even within the H zone. The mutants' rigid paralysis and sarcomeric disarray are consistent with unregulated contraction of the sarcomeres, in which small portions of each myofibril shorten irregularly and independently of one another, thereby distorting the disposition of. laments. The exacerbated deficits of su142sd worms are compatible with involvement in vivo of the N-terminal portion of troponin I in enhancing force production, and the severe impairment associated with su195sd highlights importance of the extreme C-terminus in

Hong L et al. (2001) J Cell Biol "MUP-4 is a novel transmembrane protein with functions in epithelial cell adhesion in Caenorhabditis elegans."

Bucher EA, Hong L, Ward J, Gatewood BK, Baillie DL, Franzini-Armstrong C, Elbl T, Rybicka KK

[J Cell Biol, 2001]

Tissue functions and mechanical coupling of cells must be integrated throughout development. A striking example of this coupling is the interactions of body wall muscle and hypodermal cells in Caenorhabditis elegans. These tissues are intimately associated in development and their interactions generate structures that provide a continuous mechanical link to transmit muscle forces across the hypodermis to the cuticle. Previously, we established that mup-4 is essential in embryonic epithelial (hypodermal) morphogenesis and maintenance of muscle position. Here, we report that mup-4 encodes a novel transmembrane protein that is required for attachments between the apical epithelial surface and the cuticular matrix. Its extracellular domain includes epidermal growth factor-like repeats, a von Willebrand factor A domain, and two sea urchin enterokinase modules. Its intracellular domain is homologous to filaggrin, an intermediate filament (IF)-associated protein that regulates IF compaction and that has not previously been reported as part of a junctional complex. MUP-4 colocalizes with epithelial hemidesmosomes overlying body wall muscles, beginning at the time of embryonic cuticle maturation, as well as with other sites of mechanical coupling. These findings support that MUP-4 is a junctional protein that functions in IF tethering, cell-matrix adherence, and mechanical coupling of tissues.

Zhao Y et al. (2007) BMC Genomics "Poly-G/poly-C tracts in the genomes of Caenorhabditis."

Zhao Y, O'Neil NJ, Rose AM

[BMC Genomics, 2007]

ABSTRACT: BACKGROUND: In the genome of Caenorhabditis elegans, homopolymeric poly-G/poly-C tracts (G/C tracts) exist at high frequency and are maintained by the activity of the DOG-1 protein. The frequency and distribution of G/C tracts in the genomes of C. elegans and the related nematode, C. briggsae were analyzed to investigate possible biological roles for G/C tracts. RESULTS: In C. elegans, G/C tracts are distributed along every chromosome in a non-random pattern. Most G/C tracts are within introns or are close to genes. Analysis of SAGE data showed that G/C tracts correlate with the levels of regional gene expression in C. elegans. G/C tracts are over-represented and dispersed across all chromosomes in another Caenorhabditis species, C. briggase. However, the positions and distribution of G/C tracts in C. briggsae differ from those in C. elegans. Furthermore, the C. briggsae dog-1 ortholog CBG19723 can rescue the mutator phenotype of C. elegans dog-1 mutants. CONCLUSIONS: The abundance and genomic distribution of G/C tracts in C. elegans, the effect of G/C tracts on regional transcription levels, and the lack of positional conservation of G/C tracts in C. briggsae suggest a role for G/C tracts in chromatin structure but not in the transcriptional regulation of specific genes.

Bhagwati P Gupta et al. (2002) West Coast Worm Meeting "Genetic analysis of the vulval mutants in C. briggsae"

Shahla Gharib, Bhagwati P Gupta, Paul W Sternberg, Jennifer X Li

[West Coast Worm Meeting, 2002]

To understand the evolution of developmental mechanisms, we are doing a comparative analysis of vulval patterning in C. elegans and C. briggsae. C. briggsae is closely related to C. elegans and has identical looking vulval morphology. However, recent studies have indicated subtle differences in the underlying mechanisms of development. The recent completion of C. briggsae genome sequence by the C. elegans Sequencing Consortium is extremely valuable in identifying the conserved genes between C. elegans and C. briggsae.

Antika TR et al. (2023) J Biol Chem "Sequence-specific targeting of C. elegans C-Ala to the D-loop of tRNAAla."

Horng JC, Hsu HL, Nazilah KR, Wang CC, Wang TL, Wang SC, Antika TR, Chuang TH, Chrestella DJ, Wang SW, Tseng YK, Pan HC

[J Biol Chem, 2023]

Alanyl-tRNA synthetase (AlaRS) retains a conserved prototype structure throughout its biology. Nevertheless, its C-terminal domain (C-Ala) is highly diverged and has been shown to play a role in either tRNA or DNA binding. Interestingly, we discovered that Caenorhabditis elegans cytoplasmic C-Ala (Ce-C-Ala_c) robustly binds both ligands. How Ce-C-Ala_c targets its cognate tRNA and whether a similar feature is conserved in its mitochondrial counterpart remain elusive. We show that the N- and C-terminal subdomains of Ce-C-Ala_c are responsible for DNA and tRNA binding, respectively. Ce-C-Ala_c specifically recognized the conserved invariant base G¹⁸ in the D-loop of tRNA^Ala through a highly conserved lysine residue, K934. Despite bearing little resemblance to other C-Ala domains, C. elegans mitochondrial C-Ala (Ce-C-Ala_m) robustly bound both tRNA^Ala and DNA and maintained targeting specificity for the D-loop of its cognate tRNA. This study uncovers the underlying mechanism of how C. elegans C-Ala specifically targets the D-loop of tRNA^Ala.

Blumenthal TE et al. (1994) Worm Breeder's Gazette "C. elegans U2AF 65."

Zorio DAR, Lea K, Blumenthal TE

[Worm Breeder's Gazette, 1994]

C. elegans U2AF65

Oomura, S. et al. (2019) International Worm Meeting "Early embryogenesis of C. inopinata, a sibling species of C.elegans."

Matsumura, Y., Haruta, N., Hoshi, Y., Sugimoto, A., Oomura, S.

[International Worm Meeting, 2019]

C. inopinata is a newly discovered sibling species of C. elegans. Despite their phylogenetic closeness, they have many differences in morphology and ecology. For example, while C. elegans is hermaphroditic, C. inopinata is gonochoristic; C. inopinata is nearly twice as long as C. elegans. A comparative analysis of C. elegans and C. inopinata enables us to study how genomic changes cause these phenotypic differences. In this study, we focused on early embryogenesis of C. inopinata. First, by the microparticle bombardment method we made a C. inopinata line that express GFP::histone in whole body, and compared the early embryogenesis with C. elegans by DIC and fluorescent live imaging. We found that the position of pronuclei and polar bodies were different between these two species. In C. elegans, the female and male pronuclei first become visible in anterior and posterior sides, respectively, then they meet at the center of embryo. On the other hand, the initial position of pronuclei were more closely located in C. inopinata. Also, the polar bodies usually appear in the anterior side of embryo in C. elegans, but they appeared at random positions in C. inopinata. Therefore, we infer that C. inopinata may have a different polarity formation mechanism from that in C. elegans. We are also analyzing temperature dependency of embryogenesis in C. inopinata, whose optimal temperature is ~7 degree higher than that in C. elegans.