Required for the normal progression of embryogenesis and viability of the organism. Plays an indispensable role in establishing embryonic polarity and in recruiting and maintaining par-6 to the periphery, through interaction with par-3. Required for epithelial cell polarity in the distal spermatheca. Phosphorylates serine residues of num-1. Required for the expression of antimicrobial peptide nlp-29 in response in response to fungal infection or physical injury. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Interaction with par-3 required for the peripheral localization of par-6 and to form a par-3/par-6/pkc-3 complex, which is activated when cdc-42 interacts with par-6. Binds avidly to the phosphotyrosine interaction domain (PID) of a novel pkc-3 adapter protein num-1, which enables tethering and targeting of pkc-3 to the cell periphery (By similarity). Targeted and anchored at the apical surface (villi) of intestinal and pharyngeal cells, and in proximity with the cortical actin cytoskeleton that lies under the plasma membrane. Tightly bound to organelles/cytoskeleton in six of the seven developmental stages. Accumulation in cytoplasm is restricted to L1 larvae and adults. Colocalized with par-3 at the anterior cortex of the 1-cell embryo (By similarity). Belongs to the protein kinase superfamily. AGC Ser/Thr protein kinase family. PKC subfamily.