title: The Importance of cGMP Signaling in Sensory Cilia for Body Size Regulation in Caenorhabditis elegans.
abstract: The body size of Caenorhabditis elegans is thought to be controlled by sensory inputs because many mutants with sensory cilium structure defects exhibit small body size. The EGL-4 cGMP-dependent protein kinase acts in sensory neurons to reduce body size when animals fail to perceive sensory signals. In addition to body size control, EGL-4 regulates various other behavioral and developmental pathways, including those involved in the regulation of egg laying and chemotaxis behavior. Here we have identified gcy-12, which encodes a receptor-type guanylyl cyclase, as a gene involved in the sensory regulation of body size. Analyses with GFP fusion constructs showed that gcy-12 is expressed in several sensory neurons and localizes to sensory cilia. Genetic analyses indicated that GCY-12 acts upstream of EGL-4 in body size control but does not affect other EGL-4 functions. Our studies indicate that the function of the GCY-12 guanylyl cyclase is to provide cGMP to the EGL-4 cGMP-dependent kinase only for limited tasks including body size regulation. We also found that the PDE-2 cyclic nucleotide phosphodiesterase negatively regulates EGL-4 in controlling body size. Thus, the cGMP level is precisely controlled by GCY-12 and PDE-2 to determine body size through EGL-4, and the defects in the sensory cilium structure may disturb the balanced control of the cGMP level. The large number of guanylyl cyclases encoded in the C. elegans genome suggests that EGL-4 exerts pleiotropic effects by partnering with different guanylyl cyclases for different downstream functions.
authors.affiliation: Department of Biology, Graduate School of Science, Kyushu University, fujiwara.manabi.734@m.kyushu-u.ac.jp.
authors.forename: Manabi
authors.initials: M
authors.lastname: Fujiwara
authors.affiliation: Department of Biology, Graduate School of Science, Kyushu University.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Hino
authors.affiliation: Department of Biology, Graduate School of Science, Kyushu University.
authors.forename: Ryuta
authors.initials: R
authors.lastname: Miyamoto
authors.affiliation: Department of Developmental Neuroscience, Tohoku University Graduate School of Medicine,2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Inada
authors.affiliation: Department of Biological Sciences, School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan.
authors.forename: Ikue
authors.initials: I
authors.lastname: Mori
authors.affiliation: Department of Biology, Graduate School of Science, Kyushu University.
authors.forename: Makoto
authors.initials: M
authors.lastname: Koga
authors.affiliation: Department of Applied Life Science, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1, Ikeda, Kumamoto 860-0082, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Miyahara
authors.affiliation: Department of Biology, Graduate School of Science, Kyushu University.
authors.forename: Yasumi
authors.initials: Y
authors.lastname: Ohshima
authors.affiliation: Department of Biology, Graduate School of Science, Kyushu University.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ishihara
mesh_terms: D000818:Animals; D049628:Body Size / Q000235:genetics; D017173:Caenorhabditis elegans / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000502:physiology; D002923:Cilia / Q000378:metabolism*; D006152:Cyclic GMP / Q000378:metabolism*; D017238:Genes, Helminth; D011984:Sensory Receptor Cells / Q000378:metabolism*; D015398:Signal Transduction; D013489:Suppression, Genetic
chemical_list: D029742:Caenorhabditis elegans Proteins; D006152:Cyclic GMP
keywords: Caenorhabditis elegans; body size; cGMP-dependent protein kinase; guanylyl cyclase; sensory cilia