Adipose tissue protein kinase D (PKD): regulation of signalling networks and its effect on metabolism

The protein kinase D (PKD) family of three highly homologous isoforms (PKD1, PKD2, and PKD3) are implicated as nutrient sensing signalling kinases that regulate the response of adipose and other tissues to the nutrient environment. However, the physiological role of adipose tissue PKD and the cellular signalling targets downstream of adipose tissue PKD are not well characterised. Here we employed phosphoproteomics to elucidate signalling events downstream of PKD activation in differentiated 3T3-L1 adipocytes using a triple isoform siRNA knockdown model. This identified PKD-regulated pathways including insulin and cAMP signalling, which control metabolic responses in adipose tissue.