Structural insights into the interplay of protein biogenesis factors with the 70S ribosome

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Effect of nitrosative stress on Schizosaccharomyces pombe: inactivation of glutathione reductase by peroxynitrite

Oxidative stress has been shown to alter cellular redox status in various cell types. Changes in expressions of several antioxidative and antistress-responsive genes along with activation or inactivation of various proteins were also reported during oxidative insult as well as during nitrosative stress. In the present study, we show the effect of nitrosative stress on cellular redox status of fission yeast Schizosaccharomyces pombe. This is the first report of S-nitrosoglutathione (GSNO) reductase activity in S. pombe and its inactivation by GSNO. We also show the inactivation of glutathione reductase (GR) and glutathione peroxidase in the presence of various reactive nitrogen species in vivo. In addition, we first observe the inactivation of GR by peroxynitrite in vivo using S. pombe cells and also similar observations under in vitro conditions. An immunoreactive band against monoclonal anti-3-nitrotyrosine antibody confirms the modification of GR under in vitro conditions. We also show the effect of nitrosative stress on Deltapap1 cells of S. pombe, which are more sensitive to nitrosative stress, indicating the involvement of Pap1 in the protection against nitrosative stress. Finally, exposure of S. pombe cells to reactive nitrogen species reveals an important role of cellular thiol pool in protection against nitrosative stress.     

Muscle spindles in the inferior constrictor pharyngis muscle of the crab-eating monkey (Macaca irus).

Pharyngeal muscles were considered to be lacking in spindles. A search was made for the same in the inferior constrictor pharyngis muscle of the crab-eating monkey (Macaca irus). Muscle spindles were found for the first time in this muscle. Transverse serial sections and teased preparations were obtained from this muscle belonging to six such animals, and these tissues were stained by Masson's trichrome and Ranvier's gold method, respectively. Both the methods were successful in revealing these receptors. The potential significance of this finding was discussed in relation to the activities of the pharyngeal muscles and a suggestion for a thorough re-investigation of the so-called spindleless muscles was made.