Neuronal and intestinal protein kinase d isoforms mediate Na+ (salt taste)-induced learning.
Ubiquitously expressed protein kinase D (PKD) isoforms are poised to disseminate signals carried by diacylglycerol (DAG). However, the in vivo regulation and functions of PKDs are poorly understood. We show that the Caenorhabditis elegans gene, dkf-2, encodes not just DKF-2A, but also a second previously unknown isoform, DKF-2B. Whereas DKF-2A is present mainly in intestine, we show that DKF-2B is found in neurons. Characterization of dkf-2 null mutants and transgenic animals expressing DKF-2B, DKF-2A, or both isoforms revealed that PKDs couple DAG signals to regulation of sodium ion (Na+)-induced learning. EGL-8 (a phospholipase Cbeta4 homolog) and TPA-1 (a protein kinase Cdelta homolog) are upstream regulators of DKF-2 isoforms in vivo. Thus, pathways containing EGL-8-TPA-1-DKF-2 enable learning and behavioral plasticity by receiving, transmitting, and cooperatively integrating environmental signals targeted to both neurons and intestine.
Fu
Ya
Y
Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Ren
Min
M
Feng
Hui
H
Chen
Lu
L
Altun
Zeynep F
ZF
Rubin
Charles S
CS
D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism / Q000502:physiology*; D007422:Intestines / Q000201:enzymology*; D007858:Learning / Q000187:drug effects / Q000502:physiology*; D008049:Lipase / Q000378:metabolism / Q000502:physiology; D009474:Neurons / Q000201:enzymology*; D020033:Protein Isoforms; D011493:Protein Kinase C / Q000378:metabolism / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins; D012982:Sodium, Dietary / Q000494:pharmacology; D013649:Taste / Q000502:physiology*
D029742:Caenorhabditis elegans Proteins; D020033:Protein Isoforms; D029701:Saccharomyces cerevisiae Proteins; D012982:Sodium, Dietary; C095371:TPA-1 protein, C elegans; C524695:DKF-2 protein, C elegans; C089212:protein kinase D; D011505:Protein-Tyrosine Kinases; D011493:Protein Kinase C; D008049:Lipase