A ‐kinase anchoring proteins are enriched in the central pair microtubules of motile cilia in Chlamydomonas reinhardtii

Effective motile cilia beating demands intricate coordination of various ciliary components, including proteins of the scaffold, radial spoke, and central pair. Among the scaffold proteins, A-kinase anchoring proteins (AKAPs) play a pivotal role. Thus far, the identity of central pair AKAPs has remained elusive. In our current study, we employed a blend of biochemical/biophysical methods to unveil three central pair AKAPs by utilizing an AKAP-interacting protein, FAP174, as a bait. Cilia are microtubule-based sensory organelles present in a number of eukaryotic cells. Mutations in the genes encoding ciliary proteins cause ciliopathies in humans. A-kinase anchoring proteins (AKAPs) tether ciliary signaling proteins such as protein kinase A (PKA). The dimerization and docking domain (D/D) on the RII α subunit of PKA interacts with AKAPs. Here, we show that AKAP240 from the central-pair microtubules ofChlamydomonas reinhardtii cilia uses two C-terminal amphipathic helices to bind to its partner FAP174, an RII α-like protein with a D/D domain at the N-terminus. Co-immunoprecipitation using anti-FAP174 antibody with an enriched central-pair microtubule fraction isolated seven interactors whose mass spectrometry analysis revealed proteins from the C2a (FAP65, FAP70, and FAP147) and C1b (CPC1, HSP70A, and F AP42) microtubule projections and FAP75, a protein whose sub-ciliary localization is unknown. Using RII D/D and FAP174 as baits, we identified two additional AKAPs (CPC1 and FA...

Source: FEBS Letters - February 27, 2024 Category: Biochemistry Authors: Venkatramanan G. Rao, Amruta A. Shendge, Percival P. D'Gama, Elvis A. F. Martis, Shraddha Mehta, Evans C. Coutinho, Jacinta S. D'Souza Tags: Research Article Source Type: research