D-Serine is localized in mammalian brain to a discrete population of glial cells near NMDA receptors, suggesting that D-serine is an endogenous agonist of the receptor-associated glycine site. To explore this possibility, we have compared the immunohistochemical localizations of D-serine, glycine, and NMDA receptors in rat brain. In the telencephalon, D-serine is concentrated in protoplasmic as...

NMDA receptors are activated after binding of the agonist glutamate to the NR2 subunit along with a co-agonist, either L-glycine or D-serine, to the NR1 subunit. There is substantial evidence to suggest that D-serine is the most relevant co-agonist in forebrain regions and that alterations in D-serine levels contribute to psychiatric disorders. D-serine is produced through isomerization of L-se...

During their polypeptide ligand-induced activation Stats (signaltransducers andactivators oftranscription) 1 and 3 acquire, in addition to an obligatory tyrosine phosphorylation, phosphorylation on serine which boosts their transactivating potential [Wen, Z., Zhong, Z. and Darnell, J. E. Jr. (1995) Cell 82, 241-250]. By examining phosphopeptide maps of wild-type and mutant protein we show here ...

Smooth muscle caldesmon was phosphorylated by smooth muscle calmodulin-dependent protein kinase II. The extent of phosphorylation obtained was 5.65 mol of phosphate/m01 of caldesmon. Phosphorylated protein was subjected to the complete trypsin proteolysis and the produced phosphopeptides were purified by C-8 reverse phase chromatography. Nine phosphopeptides were isolated and by amino acid sequ...

The N-methyl-D-aspartate receptor co-agonist d-serine is synthesized by serine racemase and degraded by D-amino acid oxidase. Both D-serine and its metabolizing enzymes are implicated in N-methyl-D-aspartate receptor hypofunction thought to occur in schizophrenia. We studied D-amino acid oxidase and serine racemase immunohistochemically in several brain regions and compared their immunoreactivi...

L-serine plays a versatile role in intermediary metabolism in eukaryotic cells. The physiological significance of its de novo biosynthesis, however, remains largely unexplored. We demonstrated previously that neurons lose the ability to synthesize L-serine after their final differentiation and thus depend on astrocytes to supply this amino acid. This is due to a lack of neuronal expression of 3...