A myristoyl/phosphoserine switch controls cAMP-dependent protein kinase association to membranes.

The cAMP-dependent protein kinase [protein kinase A (PKA)] mediates a myriad of cellular signaling events, and its activity is tightly regulated in both space and time. Among these regulatory mechanisms is N-myristoylation, whose biological role has been elusive. Using a combination of thermodynamics, kinetics, and spectroscopic methods, we analyzed the effects of N-myristoylation and phosphorylation at Ser10 on the interactions of PKA with model membranes.

Folding studies of Cox17 reveal an important interplay of cysteine oxidation and copper binding.

Cox17 is a key mitochondrial copper chaperone involved in the assembly of cytochrome c oxidase (COX). The NMR solution structure of the oxidized apoCox17 isoform consists of a coiled-coil conformation stabilized by two disulfide bonds involving Cys(26)/Cys(57) and Cys(36)/Cys(47). This appears to be a conserved tertiary fold of a class of proteins, localized within the mitochondrial intermembrane space, that contain a twin Cys-x(9)-Cys sequence motif.

Solution structure of Sco1: a thioredoxin-like protein Involved in cytochrome c oxidase assembly.

Sco1, a protein required for the proper assembly of cytochrome c oxidase, has a soluble domain anchored to the cytoplasmic membrane through a single transmembrane segment. The solution structure of the soluble part of apoSco1 from Bacillus subtilis has been solved by NMR and the internal mobility characterized. Its fold places Sco1 in a distinct subgroup of the functionally unrelated thioredoxin proteins.