Starvation induces cAMP response element-binding protein-dependent gene expression through octopamine-Gq signaling in Caenorhabditis elegans.

Abstract

The nervous system plays a critical role in adaptation to a new environment. In Caenorhabditis elegans, reduced access to food requires both changes in behavior as well as metabolic adaptation for survival, which is postulated to involve the bioamine octopamine. The transcription factor cAMP response element-binding protein (CREB) is generally activated by G-protein-coupled receptors (GPCRs) that activate G alpha(s) and is known to play an important role in long-term changes, including synaptic plasticity. We show that, in C. elegans, the CREB ortholog CRH-1 (CREB homolog family member 1) activates in vivo a cAMP response element-green fluorescent protein fusion reporter in a subset of neurons during starvation. This starvation response is mediated by octopamine via the GPCR SER-3 (serotonin/octopamine receptor family member 3) and is fully dependent on the subsequent activation of the G alpha(q) ortholog EGL-30 (egg-laying defective family member 30). The signaling cascade is only partially dependent on the phospholipase C beta (EGL-8) and is negatively regulated by G alpha(o) [GOA-1 (G-protein, O, alpha subunit family member 1)] and calcium/calmodulin-dependent kinase [UNC-43 (uncoordinated family member 43)]. Nonstarved animals in a liquid environment mediate a similar response that is octopamine independent. The results show that the endogenous octopamine system in C. elegans is activated by starvation and that different environmental stimuli can activate CREB through G alpha(q).

• Authors: Satoshi Suo, Yoshishige Kimura, Hubert H M Van Tol
• Journal: The Journal of neuroscience : the official journal of the Society for Neuroscience (J Neurosci) Vol. 26 Issue 40 Pg. 10082-90 (Oct 04 2006) ISSN: 1529-2401 [Electronic] United States
• PMID: 17021164 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Caenorhabditis elegans Proteins
• Cyclic AMP Response Element-Binding Protein
• Octopamine
• GTP-Binding Protein alpha Subunits, Gq-G11

Topics

• Amino Acid Sequence
• Animals
• Caenorhabditis elegans
• Caenorhabditis elegans Proteins (biosynthesis, genetics)
• Cyclic AMP Response Element-Binding Protein (biosynthesis, genetics)
• GTP-Binding Protein alpha Subunits, Gq-G11 (genetics, metabolism)
• Gene Expression Regulation (physiology)
• Male
• Molecular Sequence Data
• Octopamine (genetics, metabolism, pharmacology)
• Signal Transduction (drug effects, physiology)
• Starvation (genetics, metabolism)