Abstract
Drosophila inactivation no afterpotential D (INAD) is a PDZ domain-containing scaffolding protein that tethers components of the phototransduction cascade to form a supramolecular signaling complex. Here, we report the identification of eight INAD phosphorylation sites using a mass spectrometry approach. PDZ1, PDZ2, and PDZ4 each harbor one phosphorylation site, three phosphorylation sites are located in the linker region between PDZ1 and 2, one site is located between PDZ2 and PDZ3, and one site is located in the N-terminal region. Using a phosphospecific antibody, we found that INAD phosphorylated at Thr170/Ser174 was located within the rhabdomeres of the photoreceptor cells, suggesting that INAD becomes phosphorylated in this cellular compartment. INAD phosphorylation at Thr170/Ser174 depends on light, the phototransduction cascade, and on eye-Protein kinase C that is attached to INAD via one of its PDZ domains.
Highlights
Components of the Drosophila phototransduction cascade are tethered together by the inactivation no afterpotential D (INAD) scaffolding protein to form a supramolecular complex that is referred to as the INAD signaling complex [1,2,3,4,5,6,7,8]
We report the identification of eight INAD phosphorylation sites by a nanoHPLC-MS approach
About half of the INAD spots on 2D gels are detected by an α-T170/S174 antibody, suggesting that a significant number of the INAD molecules are phosphorylated at one of these two sites in the light
Summary
Components of the Drosophila phototransduction cascade are tethered together by the inactivation no afterpotential D (INAD) scaffolding protein to form a supramolecular complex that is referred to as the INAD signaling complex [1,2,3,4,5,6,7,8]. INAD is composed of five PDZ domains that provide the binding sites for INAD-attached proteins of the phototransduction cascade and a larger linker region between PDZ1 and PDZ2 with a putative binding site for calmodulin [9]. INAD ligands include the transient receptor potential (TRP) ion channel, phospholipase Cβ (PLCβ), eye protein kinase C (eye-PKC) [1,2,3,4,7], neither inactivation nor afterpotential C (NINAC) [10], and retinophilin (probably through binding to NINAC) [11,12]. PLOS ONE | DOI:10.1371/journal.pone.0122039 March 23, 2015
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
