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Biomedical subjects

J Kishimoto

Publications and source records attributed to J Kishimoto.

40 records · Page 3Linked to original sources
PubMed1985

Negative regulation of adenylate cyclase gene (cya) expression by cyclic AMP-cyclic AMP receptor protein in Escherichia coli: studies with cya-lac protein and operon fusion plasmids.

We constructed cya-lac protein and operon fusion plasmids in vitro. The effect of cyclic AMP (cAMP) on cya expression was examined by measuring the synthesis of beta-galactosidase in Escherichia coli cells containing fused plasmids. In the cya-lacZ fused protein system, cya expression was strongly repressed by exogenous cAMP. Functional cAMP receptor protein (CRP) was necessary for this effect. On the other hand, in a tet-lacZ fused protein as a control system, tet expression was not affected by cAMP. The inhibition of cya expression by cAMP was also observed in the cya-lac fused operon system, although it was necessary to increase the amount of cAMP or CRP in the cells to detect the effect. The results indicate that cAMP-CRP is a negative regulator of cya expression at the level of transcription.

Adenylyl Cyclases↗
PubMedDate not supplied

Age-related changes of calbindin-D28k, calretinin, and parvalbumin mRNAs in the hamster brain.

Changes of three different cytosolic Ca2+ binding proteins, calbindin-D28k, calretinin, and parvalbumin mRNA expression in the brain of the hamster during aging were investigated by in situ hybridization using brains from hamsters aged 4, 9, 13, 19, to 24 months old. In cerebellum area, calbindin-D28k transcripts showed about 50% to 68% decrease in content in aged-hamster (19 and 24 months old) compared with young (4 months) and adult (9 months), whereas calretinin and parvalbumin mRNA expression remain unchanged throughout the ages examined. Calbindin-D28k gene expression was decreased during aging also in the hippocampus (approximately 60% reduction) and striatum (approximately 25%). In the same areas, striatum and hippocampus, calretinin and parvalbumin mRNA expression in the equivalent sections were not significantly changed with age. These data raise the possibility that CNS calbindin-D28k expression may be selectively down-regulated during aging. The statistically significant decrease of calbindin-D28k mRNA in the normal aging process also suggests and provides further support for the hypothesis that this calcium binding protein may have an important role in neuronal degeneration.

Aging↗