A flagellar A-kinase anchoring protein with two amphipathic helices forms a structural scaffold in the radial spoke complex

A-kinase anchoring proteins (AKAPs) contain an amphipathic helix (AH) that binds the dimerization and docking (D/D) domain, RIIa, in cAMP-dependent protein kinase A (PKA). Many AKAPs were discovered solely based on the AH-RIIa interaction in vitro. An RIIa or a similar Dpy-30 domain is also present...

Full description

Saved in:
Bibliographic Details
Published inThe Journal of cell biology Vol. 199; no. 4; pp. 639 - 651
Main Authors Sivadas, Priyanka, Dienes, Jennifer M, St Maurice, Martin, Meek, William D, Yang, Pinfen
Format Journal Article
LanguageEnglish
Published United States Rockefeller University Press 12.11.2012
The Rockefeller University Press
Subjects
A Kinase Anchor Proteins - chemistry
A Kinase Anchor Proteins - metabolism
Cells
Cells, Cultured
Chlamydomonas reinhardtii - cytology
Chlamydomonas reinhardtii - enzymology
Chlamydomonas reinhardtii - metabolism
Flagella - enzymology
Flagella - metabolism
Hydrophobic and Hydrophilic Interactions
Kinases
Models, Molecular
Molecules
Mutagenesis
Plant Proteins
Protein Structure, Secondary
Proteins
Protozoan Proteins - chemistry
Protozoan Proteins - metabolism
Online AccessGet full text

Cover

More Information
Summary:A-kinase anchoring proteins (AKAPs) contain an amphipathic helix (AH) that binds the dimerization and docking (D/D) domain, RIIa, in cAMP-dependent protein kinase A (PKA). Many AKAPs were discovered solely based on the AH-RIIa interaction in vitro. An RIIa or a similar Dpy-30 domain is also present in numerous diverged molecules that are implicated in critical processes as diverse as flagellar beating, membrane trafficking, histone methylation, and stem cell differentiation, yet these molecules remain poorly characterized. Here we demonstrate that an AKAP, RSP3, forms a dimeric structural scaffold in the flagellar radial spoke complex, anchoring through two distinct AHs, the RIIa and Dpy-30 domains, in four non-PKA spoke proteins involved in the assembly and modulation of the complex. Interestingly, one AH can bind both RIIa and Dpy-30 domains in vitro. Thus, AHs and D/D domains constitute a versatile yet potentially promiscuous system for localizing various effector mechanisms. These results greatly expand the current concept about anchoring mechanisms and AKAPs.
ISSN:0021-9525
1540-8140
DOI:10.1083/jcb.201111042