Cloning of the gene for glutamate decarboxylase and its expression during conidiation in Neurospora crassa

Abstract

Neurospora crassa glutamate decarboxylase (GAD) is produced during conidiation and stored in dormant conidia. Polyclonal antibody was generated to GAD that had been purified to homogeneity. The anti-GAD antibody was specific for N. crassa GAD and inhibited GAD activity. The level of GAD protein decreased during conidial germination, indicating that GAD was degraded during this phase of development. The anti-GAD antibody was used to isolate a cDNA clone of GAD from a lambda ZAP cDNA expression library. Escherichia coli containing a plasmid with the cDNA insert produced GAD activity. The cDNA clone contained a 2.6 kbp insert and hybridized to a 2.6 kb mRNA species from conidiating cultures of N. crassa. GAD mRNA was not present in vegetative hyphae. In conidiating cultures, GAD mRNA was first detected when conidia began to appear. The level of GAD mRNA increased as conidiation progressed. This is the first example of the cloning of an enzyme that is regulated at the level of mRNA during the asexual developmental cycle of N. crassa.

On the Mechanism by which Alkaline pH Prevents Expression of an Acid-Expressed Gene

“…Because ␤-alanine is synthesized as a precursor for coenzyme A, the "noninduced" levels are likely to be, in effect, partially induced. An additional endogenous coinducer is likely to be GABA resulting from glutamate decarboxylation, since at least two other ascomycetes, Saccharomyces cerevisiae (see database entries Z48639.1 and U51031.1) and Neurospora crassa (19), have glutamate decarboxylases. In the presence of the intA Ϫ 101 loss-of-function mutation, the G iv 3T Ϯ G 1 3T substitutions have little or no effect.…”

Production of GABA (gamma amino butyric acid) by Lactic Acid Bacteria

“…Furthermore, GABA regulates growth hormone secretion, drops the blood pressure by expanding the blood vessels, and has the diuretic, anti-depressive, anti-oxidant effects, effective pain relief, as well as a medicine for the stroke treatment, especially (Hao and Schmit, 1993;Kono and Himeno, 2000;Leventhal et al, 2003;Shelp et al, 1999). In recent years, its sleep-inducing effect was proved by the animal experiment which establishes the production of serotonin and melatonin which act as sleep inducer, is facilitated significantly in the GABA-containing milk feeding group .…”

Characterization of Glutamate Decarboxylase from a High γ-Aminobutyric Acid (GABA)-Producer,Lactobacillus paracasei

“…4,5) GABA production by various microorganisms has been reported, including bacteria, 6,7) fungi, 8) and yeasts. 9) We focused on the GABA production ability of lactic acid bacteria (LAB) because LAB possess commercial potential as a starter of production in fermented foods such as pickled vegetables and fermented meats and fishes. We have reported that Lactobacillus paracasei isolated from a traditional Japanese fermented fish ( funa-sushi) showed high GABA-producing ability.…”