Rho participates in chemoreceptor-induced changes in morphology to hair bundle mechanoreceptors of the sea anemone, Nematostella vectensis

• Published in: Comparative biochemistry and physiology. Part A, Molecular & integrative physiology Vol. 165; no. 2; pp. 139 - 148
• Main Authors: Allaire, Kathryn M., Watson, Glen M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2013
• Subjects: Actin Cytoskeleton - metabolism; Amino Acid Sequence; Animals; Anthozoa; Blotting, Western; Calcimycin - pharmacology; Calcium Ionophores - pharmacology; cell communication; Cell Communication - drug effects; Cell Communication - physiology; Chemoreceptor Cells - drug effects; Chemoreceptor Cells - metabolism; Chemoreceptor Cells - physiology; chemoreceptors; Cyclic-AMP; Epidermis - cytology; Epidermis - metabolism; G-protein coupled receptors; Gap junctions; Gap Junctions - drug effects; Gap Junctions - metabolism; Gap Junctions - physiology; genome; Heptanol - pharmacology; immunocytochemistry; Immunohistochemistry; mechanoreceptors; Mechanoreceptors - cytology; Mechanoreceptors - metabolism; Mechanoreceptors - physiology; microfilaments; Models, Biological; Molecular Sequence Data; N-Acetylneuraminic Acid - pharmacology; Nematostella vectensis; proline; Rho; rho GTP-Binding Proteins - genetics; rho GTP-Binding Proteins - metabolism; Sea Anemones - cytology; Sea Anemones - metabolism; Sea Anemones - physiology; Signal Transduction - drug effects; sugars; swimming; Western blotting; PBS; NANA; G-protein coupled receptors; Nematostella vectensis; Gap junctions; PKA; TBST; GEF; CaM-kinase; CN; Cyclic-AMP; GDI; IP3; KSW; BSA; Rho; GPCR
• ISSN: 1095-6433; 1531-4332
• DOI: 10.1016/j.cbpa.2013.03.003

Adjustable hair bundle mechanoreceptors located on anemone tentacles detect movements of nearby, swimming prey. The hair bundles are formed by numerous actin-based stereocilia that converge onto a single, central kinocilium. Interestingly, morphological and functional changes to the hair bundles are induced by activating chemoreceptors that bind prey-derived N-acetylated sugars and proline, respectively. Morphological changes to the hair bundles involve alterations to the actin cytoskeleton of stereocilia. A pharmacological activation of Rho induces hair bundles to elongate to lengths comparable to those normally induced by exposure to N-acetylneuraminic acid (NANA) and prevents shortening of hair bundles normally induced by proline. Rho inhibition prevents NANA-induced elongation, but does not prevent proline-induced shortening of hair bundles. Western blots feature a band similar in mass to that predicted for a Rho homolog in the genome of Nematostella. Immunocytochemistry localizes Rho in stereocilia of the hair bundle. Anemone hair bundles arise from multicellular complexes. Data from experiments using heptanol, a gap junction uncoupler, indicate that cell–cell communication is required in order for activated chemoreceptors to induce morphological changes to the hair bundles.