Molecules interacting with PRIP-2, a novel Ins(1,4,5)P3 binding protein type 2: Comparison with PRIP-1.
A family of phospholipase C-related, catalytically inactive proteins (designated PRIP) have been identified as a group of novel inositol 1,4,5-trisphosphate binding proteins with a domain organization similar to phospholipase C-delta but lacking the enzymatic activity. The PRIP family consists of at least two types of proteins (PRIP-1 and PRIP-2 subfamilies). In the present study, we examined the tissue distribution of PRIP-2, its expression in rat brain at the mRNA level, and the characteristics of its binding to inositol compounds, protein phosphatase 1, and gamma-amino butyric acid receptor associated protein. We also compared these characteristics with those of PRIP-1. Northern blot analysis and reverse-transcription polymerase chain reaction showed that PRIP-1 was present mainly in the brain, whereas PRIP-2 was expressed ubiquitously. In situ hybridization studies using rat brain revealed that the mRNA for both PRIP-1 and PRIP-2 was similarly expressed; it was detected in the granular cell and Purkinje cell layers in the cerebellum, and in the hippocampal pyramidal cells, dentate granule cells, and pyramidal and/or granule cells of the cerebral cortex in the cerebrum. PRIP-2 bound inositol 1,4,5-trisphosphate and its parent lipid, phosphatidylinositol 4,5-bisphosphate, with a similar affinity, while PRIP-1 preferentially bound the former ligand by about 10-fold. PRIP-1 and PRIP-2 interacted with protein phosphatase 1 and gamma-amino butyric acid receptor associated protein in a similar manner. These results indicate that, similar to PRIP-1, PRIP-2 may be involved in both inositol 1,4,5-trisphosphate-mediated and gamma-amino butyric acid-related signaling.
Uji
Ayako
A
Laboratory of Molecular and Cellular Biochemistry and Station for Collaborative Research, Faculty of Dental Science, Kyushu University, 812-8582, Fukuoka, Japan.
Matsuda
Miho
M
Kukita
Toshio
T
Maeda
Katsumasa
K
Kanematsu
Takashi
T
Hirata
Masato
M
D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D015152:Blotting, Northern; D015220:Calcium Channels / Q000378:metabolism*; D004247:DNA / Q000032:analysis; D015870:Gene Expression / Q000187:drug effects; D017403:In Situ Hybridization; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D053496:Inositol 1,4,5-Trisphosphate Receptors; D015345:Oligonucleotide Probes; D011485:Protein Binding; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D011963:Receptors, GABA-A / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology
D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D011963:Receptors, GABA-A; D011994:Recombinant Proteins; D015544:Inositol 1,4,5-Trisphosphate; D004247:DNA