Another interesting and important class of PKC binding partners have been termed STICKs (substrates interacting with C kinase) (Jaken and Parker 2000). This group of proteins exhibits high-affinity interactions with regulatory domains on PKC, but they are also good substrates for PKC. Intriguingly, some STICKs also bind phosphatidylserine, and others bind F-actin, suggesting opportunities for multisite interactions to enhance PKC targeting. Among the widely studied members of this group are MARCKS (myristolyated alanine rich C-kinase substrate) (Fujise et al. 1994), vinculin/talin (Hyatt et al. 1994), GAP43 (Dekker and Parker 1997), gravin (Nauert et al. 1997), AKAP79 (Klauck et al. 1996) and annexins (Hyatt et al. 1994). These proteins interact with PKC isoforms in at least two ways, through PKC's regulatory domains for high-affinity binding and through PKC's catalytic domain to become phosphorylated.

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