TRP and the PDZ protein, INAD, form the core complex required for retention of the signalplex in Drosophila photoreceptor cells

TitleTRP and the PDZ protein, INAD, form the core complex required for retention of the signalplex in Drosophila photoreceptor cells
Publication TypeJournal Article
Year of Publication2000
AuthorsLi HS, Montell C
JournalJ Cell Biol
Volume150
Pagination1411-22
Date Published2000 Sep 18
ISSN0021-9525
KeywordsAge Factors, Amino Acid Sequence, Animals, Animals, Genetically Modified, Binding Sites, Calcium Channels, Drosophila, Drosophila Proteins, Electrooculography, Eye Proteins, Molecular Sequence Data, Mutagenesis, Photoreceptor Cells, Invertebrate, Protein Kinase C, Protein Structure, Tertiary, Synapses, TRPC Cation Channels, Type C Phospholipases, Vision, Ocular
Abstract

The light response in Drosophila photoreceptor cells is mediated by a series of proteins that assemble into a macromolecular complex referred to as the signalplex. The central player in the signalplex is inactivation no afterpotential D (INAD), a protein consisting of a tandem array of five PDZ domains. At least seven proteins bind INAD, including the transient receptor potential (TRP) channel, which depends on INAD for localization to the phototransducing organelle, the rhabdomere. However, the determinants required for localization of INAD are not known. In this work, we showed that INAD was required for retention rather than targeting of TRP to the rhabdomeres. In addition, we demonstrated that TRP bound to INAD through the COOH terminus, and this interaction was required for localization of INAD. Other proteins that depend on INAD for localization, phospholipase C and protein kinase C, also mislocalized. However, elimination of any other member of the signalplex had no impact on the spatial distribution of INAD. A direct interaction between TRP and INAD did not appear to have a role in the photoresponse independent of localization of multiple signaling components. Rather, the primary function of the TRP/ INAD complex is to form the core unit required for localization of the signalplex to the rhabdomeres.

Alternate JournalJ. Cell Biol.
PubMed ID10995445
PubMed Central IDPMC2150714
Grant ListEY08117 / EY / NEI NIH HHS / United States
EY10852 / EY / NEI NIH HHS / United States