Activation of the mouse inositol 1,4,5-trisphosphate receptor type 1 promoter by AP-2.
Inositol 1,4,5-trisphosphate receptor (IP3R) functions as a Ca2+ channel that increases the intracellular Ca2+ upon binding to inositol trisphosphates. IP3R is expressed ubiquitously and consists of a multigene family. Since the type 1 IP3R (IP3R1) is highly expressed in the cerebellar Purkinje cells and moderately in hippocampus in the mammalian central nervous system (CNS), it is regarded as a neural member of this gene family. In this work, we investigated transcriptional regulation of the mouse ip3r1 gene. A DNaseI footprinting assay demonstrated that a sequence from -95 to -75, designated as box-II, was a binding site for a cerebellum-enriched factor. A consensus sequence for AP-2 was located in box-II. An electrophoretic mobility shift assay with anti-AP-2 antibody revealed that AP-2 is capable of binding to box-II. Deletion analysis of box-II showed that flanking sequences beside the box-II motif were required for the stable binding. We demonstrated by transient luciferase assay that exogenously expressed AP-2 activated box-II-dependent transcription. Moreover, we showed that endogenous AP-2 induced by retinoic acid also activated transcription via box-II in P19 cells. In-situ hybridization of the mouse brain revealed that AP-2 was predominantly expressed in the cerebellar Purkinje cells and hippocampal CA1 region, where IP3R1 is also highly expressed. From these observations, AP-2 binding to box-II is thought to be responsible for IP3R1 gene regulation in the CNS.
Ohkawa
N
N
Department of Biology, Faculty of Science, Chiba University, Yayoi-cho Inage-Ku, Chiba, 263-8522, Japan.
Konishi
Y
Y
Shimada
M
M
Makino
Y
Y
Yoshikawa
S
S
Mikoshiba
K
K
Tamura
T
T
D000818:Animals; D001665:Binding Sites / Q000235:genetics; D001921:Brain / Q000378:metabolism; D015220:Calcium Channels / Q000235:genetics*; D002460:Cell Line; D018983:DNA Footprinting; D004268:DNA-Binding Proteins / Q000235:genetics*; D003850:Deoxyribonuclease I / Q000378:metabolism; D005786:Gene Expression Regulation / Q000235:genetics; D017930:Genes, Reporter / Q000235:genetics; D017403:In Situ Hybridization; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008099:Liver / Q000378:metabolism; D051379:Mice; D009687:Nuclear Proteins / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D050656:Transcription Factor AP-2; D014157:Transcription Factors / Q000235:genetics*; D015533:Transcriptional Activation / Q000235:genetics; D014212:Tretinoin / Q000494:pharmacology
D015220:Calcium Channels; D004268:DNA-Binding Proteins; D053496:Inositol 1,4,5-Trisphosphate Receptors; D009687:Nuclear Proteins; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D050656:Transcription Factor AP-2; D014157:Transcription Factors; D014212:Tretinoin; D003850:Deoxyribonuclease I