Plays a role in promoting axonal degeneration following neuronal injury by toxic insult or trauma (PubMed:22496551). Organizes rhabdomeric components to suppress random activation of the phototransduction cascade and thus increases the signaling fidelity of dark-adapted photoreceptors (PubMed:20107052). The rtp/ninaC complex is required for stability of inad and inac and the normal termination of phototransduction in the retina (PubMed:20739554). Interacts with ninaC. Co-localizes with ninaC in the rhabdomere membrane. Retina. Expressed primarily in the phototransducing compartment of photoreceptor cells, the rhabdomeres and its expression is dependent on ninaC protein (at protein level). phosphorylated under dark conditions and is dephosphorylated by light exposure. Severed rtp null axons show significantly reduced and delayed axonal degeneration following axotomy whereas wild-type axons degenerate within the first 24 hrs (PubMed:22496551). Rtp-null mutant flies exhibit age-dependent impairment in the termination of phototransduction in the retina (PubMed:20739554). Photoreceptors show a conspicuously high level of spontaneous dark noise (PubMed:20107052).