4x6q

Publication Abstract from PubMed

Cyclic AMP-dependent protein kinase (PKA) is regulated in part by N-terminal myristylation of its catalytic (C) subunit. Structural information about the role of myristylation in membrane targeting of PKA has been limited. In mammalian cells there are four functionally non-redundant PKA regulatory subunits (RIalpha, RIbeta, RIIalpha, and RIIbeta). PKA is assembled as an inactive R2C2 holoenzyme in cells. To explore the role of N-myristylation in membrane targeting of PKA holoenzymes, we solved crystal structures of RIalpha:myrC and RIIbeta2:myrC2, and showed that the N-terminal myristylation site in the myrC serves as a flexible "switch" that can potentially be mobilized for membrane anchoring of RII, but not RI, holoenzymes. Furthermore, we synthesized nanodiscs and showed by electron microscopy that membrane targeting through the myristic acid is specific for the RII holoenzyme. This membrane-anchoring myristylation switch is independent of A Kinase Anchoring Proteins (AKAPs) that target PKA to membranes by other mechanisms.

An Isoform-Specific Myristylation Switch Targets Type II PKA Holoenzymes to Membranes.,Zhang P, Ye F, Bastidas AC, Kornev AP, Wu J, Ginsberg MH, Taylor SS Structure. 2015 Aug 5. pii: S0969-2126(15)00288-9. doi:, 10.1016/j.str.2015.07.007. PMID:26278174^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.