The C. elegans gon-2 gene encodes a putative TRP cation channel protein required for mitotic cell cycle progression

doi:10.1016/S0378-1119(01)00373-0

Gene

Volume 266, Issues 1–2, 21 March 2001, Pages 103-110

https://doi.org/10.1016/S0378-1119(01)00373-0 Get rights and content

Abstract

The C. elegans gon-2 gene is required for the post-embryonic mitotic cell divisions of the gonadal precursor cells. A single major transcript of approximately 6.7 kb is derived from the gon-2 locus. This mRNA encodes a protein related to the TRP family of cation channels and has a high degree of similarity to several vertebrate genes, including melastatin. Mutant alleles of gon-2 affect evolutionarily conserved amino acid residues. Northern analyses suggest that gon-2 expression is not limited to gonadal tissues.

Introduction

The gonad of the C. elegans hermaphrodite is derived from two somatic precursor cells, Z1 and Z4, and two germline precursors, Z2 and Z3. These cells begin mitotic divisions midway through the first larval stage. Z1 and Z4 eventually give rise to 143 somatic descendants, while Z2 and Z3 divide to produce approximately one thousand germ cells (Kimble and Hirsh, 1979). Mutations in the gon-2 gene cause a variable delay or absence of mitotic divisions among the gonadal precursor cells without causing any apparent direct defects in non-gonadal tissues (Sun and Lambie, 1997).

In order to begin to understand how gon-2 regulates gonadal cell divisions, we have examined the structure and expression pattern of the mRNA derived from the wild type locus. We have also determined the sequence alterations associated with five mutant alleles.

Section snippets

Worm culture methods

Nematodes were cultured in Petri dishes on NGM-Lite medium (Sun and Lambie, 1997), with Escherichia coli strain OP50 (Brenner, 1974) or AMA1004 (Casadaban et al., 1993) as a food source. Stocks were maintained at 15, 20, or 25°C depending on the experiment.

Transformation rescue assays

Cosmids were assayed for their ability to rescue gon-2(q388) by co-injection with the ROL-6 plasmid pRF4 as a transformation marker (Mello and Fire, 1995, Mello et al., 1991). Cosmids were injected singly or in pools into gravid adult

gon-2 corresponds to T01H8.5

In previous work, we mapped gon-2 to a position midway between fer-1 and ceh-6 on the right arm of chromosome I (Sun and Lambie, 1997). This region is spanned by multiple cosmid clones. We assayed cosmids, either singly or in pools, for their ability to provide transformation rescue of the mutant allele gon-2(q388) (Fig. 1). Efficient rescuing activity was obtained only when cosmids T01H8 and F59D11 were coinjected, although T01H8 provided weak rescue when injected alone (data not shown). This

Conclusions

1.
gon-2 encodes a member of the TRP family of proteins that is necessary for postembryonic mitotic cell divisions of the gonadal precursor cells of C. elegans.
2.
Expression of the gon-2 transcript is not limited to the gonad, although mutations in gon-2 do not affect other tissues.
3.
gon-2 has close relatives in C. elegans, human, mouse, and D. melanogaster.
4.
Each gon-2 mutation that we have identified affects a conserved amino acid residue, suggesting that these residues are important for the activity

Acknowledgements

This work was supported by NIH grant RO1-GM49785. We are grateful to Alan Coulson for numerous cosmid clones and Bob Barstead for the gift of his cDNA library. We also thank Karen Bennett for the eIF4a clone, and reviewers for helpful comments on the manuscript.

References (31)

S.F. Altschul et al.
Basic local alignment search tool
J. Mol. Biol.
(1990)
J. Chevesich et al.
Requirement for the PDZ domain protein, INAD, for localization of the TRP store-operated channel to a signaling complex
Neuron
(1997)
C. Harteneck et al.
From worm to man: three subfamilies of TRP channels
Trends Neurosci.
(2000)
J.J. Hunter et al.
Chromosomal localization and genomic characterization of the mouse melastatin gene (Mlsn1)
Genomics
(1998)
S.K. Kim
Polarized signaling: basolateral receptor localization in epithelial cells by PDZ-containing proteins
Curr. Opin. Cell Biol.
(1997)
J. Kimble et al.
The postembryonic cell lineages of the hermaphrodite and male gonads in Caenorhabditis elegans
Dev. Biol.
(1979)
M. Krause et al.
A trans-spliced leader sequence on actin mRNA in C. elegans
Cell
(1987)
C. Mello et al.
DNA Transformation
K. Nagamine et al.
Molecular cloning of a novel putative Ca²⁺ channel protein (TRPC7) highly expressed in brain
Genomics
(1998)
R. Ranganathan et al.
PDZ domain proteins: scaffolds for signaling complexes
Curr. Biol.
(1997)

J. Saras et al.

PDZ domains bind carboxy-terminal sequences of target proteins

Trends Biochem. Sci.

(1996)

J.S. Simske et al.

LET-23 receptor localization by the cell junction protein LIN-7 during C. elegans vulval induction

Cell

(1996)

N. Takuwa et al.

Calcium, calmodulin and cell cycle progression

Cell Signal

(1995)

F. Ausubel

S. Bektesh et al.

Presence of the Caenorhabditis elegans spliced leader on different mRNAs and in different genera of nematodes

Genes Dev.

(1988)

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Four TRPM genes have been described in C. elegans (Xiao and Xu, 2009). Of these, gon-2 and gtl-1 have been implicated in intestinal electrolyte homeostasis, postembryonic mitosis in the gonad, and body wall contraction (Kwan et al., 2008; Teramoto et al., 2005; West et al., 2001). The zebrafish genome encodes four TRPM genes; a mutant in trpm7 shows defects in skeletogenesis, embryonic melanophore formation, growth, and touch responses (Elizondo et al., 2005).
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In C. elegans, TRPC channels have been shown to play a role in this process. The product of the gon‐2 gene, GON‐2, a TRPM member, has been shown to be required for the postembryonic mitotic cell divisions of the gonadal precursor cells (West et al., 2001) and TRPC3 channels have been suggested to mediate Ca2+ influx during sperm–egg plasma membrane interactions leading to fertilization (Xu and Sternberg, 2003). In mouse pulmonary vascular smooth muscle cells, PDGF‐induced proliferation involves upregulation of TRPC6 expression, which has been suggested to play a key role in the enhancement of cell growth by increasing Ca2+ entry and replenishing the intracellular Ca2+ stores (Yu et al., 2003).
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Other members of the TRP ion channel family in C. elegans include GON‐2 and GTL‐1 which belong to the TRPM group and are localized in intestinal epithelial cells, where they control electrolyte homeostasis (Teramoto et al., 2005). GON‐2 is also required for proper gonadal development (Sun and Lambie, 1997; West et al., 2001; Church and Lambie, 2003). C. elegans TRP‐1, TRP‐2, and TRP‐3 are similar to TRPC ion channels.
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We also found that a full-length fusion between gtl-1 and GFP was expressed throughout the intestine, with accumulation at the apical surface toward the intestinal lumen (Figure S3). Previously, two different 5′ ends of the gon-2 transcript were described (one starts at nt 20643 and the other at nt 9278 of cosmid T01H8) (West et al., 2001). Here we found that GFP fluorescence was strongly expressed in the intestine when we used the potential promoter region containing the initiation site for the shorter transcript (the promoter for the longer transcript expressed GFP in other cell types; Figure S4).
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A variety of lipid and lipid-derived molecules can modulate TRP cation channel activity, but the identity of the lipids that affect TRP channel function in vivo is unknown. Here, we use genetic and behavioral analysis in the nematode C. elegans to implicate a subset of 20-carbon polyunsaturated fatty acids (PUFAs) in TRPV channel-dependent olfactory and nociceptive behaviors. Olfactory and nociceptive TRPV signaling are sustained by overlapping but nonidentical sets of 20-carbon PUFAs including eicosapentaenoic acid (EPA) and arachidonic acid (AA). PUFAs act upstream of TRPV family channels in sensory transduction. Short-term dietary supplementation with PUFAs can rescue PUFA biosynthetic mutants, and exogenous PUFAs elicit rapid TRPV-dependent calcium transients in sensory neurons, bypassing the normal requirement for PUFA synthesis. These results suggest that a subset of PUFAs with omega-3 and omega-6 acyl groups act as endogenous modulators of TRPV signal transduction.

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The C. elegans gon-2 gene encodes a putative TRP cation channel protein required for mitotic cell cycle progression

Abstract

Introduction

Section snippets

Worm culture methods

Transformation rescue assays

gon-2 corresponds to T01H8.5

Conclusions

Acknowledgements

J. Mol. Biol.

Neuron

Trends Neurosci.

Genomics

Curr. Opin. Cell Biol.

Dev. Biol.

Cell

Genomics

Curr. Biol.

Trends Biochem. Sci.

Cell

Cell Signal

Presence of the Caenorhabditis elegans spliced leader on different mRNAs and in different genera of nematodes

Genes Dev.