The delta subunit of rod specific cyclic GMP phosphodiesterase, PDE delta, interacts with the Arf-like protein Arl3 in a GTP specific manner.
Recently, we have shown that the delta subunit of the cGMP phosphodiesterase (PDE delta) interacts with the retinitis pigmentosa guanine regulator (RPGR). Here, using the two-hybrid system, we identify a member of the Arf-like protein family of Ras-related GTP-binding proteins, Arl3, that interacts with PDE delta. The interaction was verified by fluorescence spectroscopy and co-immunoprecipitation. Arl3 features an unusually low affinity for guanine nucleotides, with a KD of 24 nM for GDP and 48 microM for GTP. Fluorescence spectroscopy shows that PDE delta binds and specifically stabilizes the GTP-bound form of Arl3 by strongly decreasing the dissociation rate of GTP. Thus, PDE delta is an effector of Arl3 and could provide a novel nucleotide exchange mechanism by which PDE delta stabilizes Arl3 in its active GTP-bound form.
Linari
M
M
Max-Planck-Institut für Molekulare Physiologie, Abteilung Strukturelle Biologie, Dortmund, Germany.
Hanzal-Bayer
M
M
Becker
J
J
D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000378:metabolism* / Q000502:physiology*; D020727:ADP-Ribosylation Factors / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D054707:Cyclic Nucleotide Phosphodiesterases, Type 6; D005136:Eye Proteins / Q000378:metabolism* / Q000502:physiology*; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D051379:Mice; D016296:Mutagenesis; D010957:Plasmids; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014162:Transfection; D020798:Two-Hybrid System Techniques
D005136:Eye Proteins; D006160:Guanosine Triphosphate; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054707:Cyclic Nucleotide Phosphodiesterases, Type 6; C517431:PDE6B protein, human; C517438:Pde6b protein, mouse; C490248:Arl3 protein, mouse; D020727:ADP-Ribosylation Factors; C490247:ARL3 protein, human