We have shown previously that vanadate stimulates overall endogenous phosphorylation of proteins in subcellular particulate fractions. In brain mitochondria there is a single peptide band of Mr (approx.) 34 kDa, phosphorylation of which is inhibited rather than stimulated by both vanadate and vanadyl ions. Here, further characterization of this unique effect of vanadium ions is reported. Phosphorylation of the 34 kDa protein proceeds in the Triton X-100 extracts of mitochondria. The P-labeled 34 kDa band was recovered from TCA sediments of endogenously phosphorylated mitochondria. Acid lability of the phosphate linkage suggests a bond of P-N type. Phosphorylation of the 34 kDa protein is highly sensitive to Mg2+, while Mn2+ is a less potent activator. The results provide further evidence for existence of a protein occurring exclusively in mitochondria, the phosphorylation of which is selectively modified by both vanadate anion and vanadyl cation in a way differing from those hitherto described.

• MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• fosforylace MeSH
• kationty farmakologie   MeSH
• krysa rodu Rattus MeSH
• mitochondrie účinky léků   MeSH
• molekulová hmotnost MeSH
• mozková kůra účinky léků   metabolismus   MeSH
• proteiny nervové tkáně metabolismus   MeSH
• techniky in vitro MeSH
• vanad farmakologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kationty MeSH
• proteiny nervové tkáně MeSH
• vanad MeSH

It has been shown previously (1) that vanadate stimulates phosphorylation of the overall proteins from the synaptic membranes of rat cerebral cortex. The aim of the present experiments was to investigate whether the action of vanadate and also of vanadyl ions could exert any specific effect on endogenous phosphorylation of proteins from subcellular fractions of the rat brain cortex. Both vanadate and vanadyl ions stimulate phosphorylation of the overall proteins from synaptic membranes and to lesser extent from mitochondria. An attempt was made to estimate the contribution of inhibition of ATPase activity to nonspecific stimulation of phosphate labeling in the synaptic membrane fraction. A band of Mr approx. 37 kDa from synaptic membranes was particularly sensitive to vanadate. In mitochondria both vanadate and vanadyl caused a marked, concentration dependent inhibition of phosphorylation of a band corresponding to Mr approx. 34 kDa. The effect was confined exclusively to the mitochondrial fractions (total, perikaryal and two synaptic types). It was absent in all subcellular fractions tested, including the nuclear one. Phosphorylation of the mitochondrial 34 kDa band is not influenced by cyclic AMP, Ca-calmodulin, shift of pH from 6.6 to 8.1. Alkaline hydrolysis removed almost all phosphate-labeled bands of mitochondria, including that of 34 kDa.

• MeSH
• adenosintrifosfát metabolismus   MeSH
• fosforylace MeSH
• kinetika MeSH
• krysa rodu Rattus MeSH
• membránové proteiny metabolismus   MeSH
• mozková kůra účinky léků   metabolismus   MeSH
• proteiny nervové tkáně metabolismus   MeSH
• radioizotopy fosforu MeSH
• sloučeniny vanadu * MeSH
• subcelulární frakce metabolismus   MeSH
• synaptické membrány účinky léků   metabolismus   MeSH
• vanad farmakologie   MeSH
• vanadáty farmakologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adenosintrifosfát MeSH
• membránové proteiny MeSH
• proteiny nervové tkáně MeSH
• radioizotopy fosforu MeSH
• sloučeniny vanadu * MeSH
• vanad MeSH
• vanadáty MeSH
• vanadyl sulfate MeSH Prohlížeč