The redundancy and diversity between two novel PKC isotypes that regulate learning in Caenorhabditis elegans

Significance The nervous system can store an experience of sensory stimulus. This function (i.e., learning) requires a robust molecular mechanism because accurate readout of information is crucial in survival. In this study, we found that the gustatory learning ofCaenorhabditis elegans implemented as the amount of diacylglycerol in the sensory neuron can be read out not only by the activity of PKC-1, a protein kinase C, but also by that of another PKC, TPA-1. Because of its low sensitivity to diacylglycerol, TPA-1 does not function in the conventional learning assay. However, under conditions that may impair the system, such as aging, TPA-1 contributes to the learning. Our study shows the robustness of the learning system achieved by the two PKCs.