title: MafG-2 is a novel Maf protein that is expressed by stimulation of extracellular H(+).
abstract: We cloned MafG-2, a novel splice variant of MafG, from rat brain by RT-PCR method. MafG-2 differs from the previously published MafG by an insertion of 27 amino acids. Sequence analysis of the cDNA-encoded MafG-2 showed that MafG-2 contains basic domain and basic leucine zipper (bZip) motif. Transient transfection studies with GFP-MafG-2 chimera protein indicate that MafG-2 is localized in the nuclei of transfected COS-7 cells. To determine whether gene expression of mafG-2 mRNA is induced by an increase in extracellular protons, we analyzed expression of the mRNA in PC12 cells after an increase in extracellular proton concentration. We found that the mafG-2 mRNA expression increased when extracellular pH was decreased gradually from 7.40 to 7.20 and that there was a significant correlation between extracellular pH value and the expression of mafG-2 mRNA. These results suggest that an increase in extracellular proton may induce the expression of mafG-2 mRNA and MafG-2 may be involved in signal transduction of extracellular of H(+).
authors.affiliation: Physiology 1st Division, Gunma University School of Medicine, 3-39-22 Showa-machi, 371-8511, Maebashi, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Shimokawa
authors.forename: I
authors.initials: I
authors.lastname: Kumaki
authors.forename: K
authors.initials: K
authors.lastname: Takayama
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics*; D005110:Extracellular Space / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D051259:MafG Transcription Factor; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000235:genetics*; D016716:PC12 Cells; D010802:Phylogeny; D011522:Protons; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D012097:Repressor Proteins / Q000096:biosynthesis / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics*; D015533:Transcriptional Activation
chemical_list: D004268:DNA-Binding Proteins; D051259:MafG Transcription Factor; C491247:Mafg protein, mouse; C491246:Mafg protein, rat; D009687:Nuclear Proteins; D011522:Protons; D012333:RNA, Messenger; D012097:Repressor Proteins; D014157:Transcription Factors