A multivalent PDZ-domain protein assembles signalling complexes in a G-protein-coupled cascade.
How are signalling molecules organized into different pathways within the same cell? In Drosophila, the inaD gene encodes a protein consisting of five PDZ domains which serves as a scaffold to assemble different components of the phototransduction cascade, including the principal light-activated ion channels, the effector phospholipase C-beta and protein kinase C. Null inaD mutants have a dramatically reorganized subcellular distribution of signalling molecules, and a total loss of transduction complexes. Also, mutants defective in a single PDZ domain produce signalling complexes that lack the target protein and display corresponding defects in their physiology. A picture emerges of a highly organized unit of signalling, a 'transduclisome', with PDZ domains functioning as key elements in the organization of transduction complexes in vivo.
Tsunoda
S
S
Howard Hughes Medical Institute, and Department of Biology, University of California at San Diego, La Jolla 92093-0649, USA.
Sierralta
J
J
Sun
Y
Y
Bodner
R
R
Suzuki
E
E
Becker
A
A
Socolich
M
M
Zuker
C S
CS
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D015220:Calcium Channels / Q000378:metabolism; D004330:Drosophila; D029721:Drosophila Proteins; D004594:Electrophysiology; D005136:Eye Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005260:Female; D019204:GTP-Binding Proteins / Q000378:metabolism*; D019476:Insect Proteins / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D017956:Photoreceptor Cells, Invertebrate / Q000378:metabolism / Q000648:ultrastructure; D011493:Protein Kinase C / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D050051:Transient Receptor Potential Channels; D010738:Type C Phospholipases / Q000378:metabolism; D014785:Vision, Ocular
D015220:Calcium Channels; D029721:Drosophila Proteins; D005136:Eye Proteins; D019476:Insect Proteins; D050051:Transient Receptor Potential Channels; C091568:inaD protein, Drosophila; C063169:trp protein, Drosophila; D011493:Protein Kinase C; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins