Wnt and calcium signaling: beta-catenin-independent pathways.
Wnt signaling is a complex pathway in which beta-catenin is typically viewed as a central mediator. However, within the past 15 years, at least three Wnt-mediated pathways have been proposed that function independent of beta-catenin. One pathway involves activation of calcium/calmodulin-dependent kinase II (CamKII) and protein kinase C (PKC). Another includes recruitment of heterotrimeric GTP-binding proteins to activate phospholipase C (PLC) and phosphodiesterase (PDE). Lastly, a pathway similar to the planar cell polarity (PCP) pathway in Drosophila has been identified that activates the Jun-N-terminal kinase (JNK) and, perhaps, small GTP-binding proteins. Calcium has been implicated as an important second messenger in all of these pathways. This review will focus on the role of calcium in Wnt signaling and, as a consequence, provide a limited overview of beta-catenin-independent Wnt signaling.
Kohn
Aimee D
AD
Howard Hughes Medical Institute, Division of Hematology, Department of Pharmacology, and the Center for Developmental Biology, University of Washington School of Medicine, Box 357750, Seattle, WA 98195, USA.
Moon
Randall T
RT
D000818:Animals; D020013:Calcium Signaling / Q000502:physiology*; D006801:Humans; D015398:Signal Transduction / Q000502:physiology; D051153:Wnt Proteins / Q000737:chemistry / Q000502:physiology*; D051176:beta Catenin / Q000737:chemistry / Q000502:physiology*
D051153:Wnt Proteins; D051176:beta Catenin