Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P62988 (Ubiquitin)
 4,326 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ubiquitin, an essential protein in nonlysosomal proteolytic system, is expressed after metabolic stress to the cell. The authors investigated stress response of ubiquitin in the hippocampus of the Mongolian gerbil after forebrain ischemia. The level of hippocampal ubiquitin was compared with that under ischemic tolerance induced by ischemic preconditioning. The authors also studied ubiquitin gene expression using in situ hybridization method. Transient ischemia resulted in consumption of free ubiquitin and an increase of multiubiquitin chains. These changes were transient in the hippocampus outside of the CA1 region where neurons survived, whereas it was persistent in the CA1 region where neurons were destined to die after ischemia. Under tolerant condition, subsequent ischemia provoked rapid recovery and further increase of free ubiquitin. The signal of ubiquitin messenger ribonucleic acid was continuously detected after ischemia, not only under tolerant conditions, but without tolerance induced by preconditioning. Thus, ubiquitin stress response takes place, at least at a transcriptional level, in dying CA1 neurons. Under tolerant conditions, however, subsequent ischemia in the CA1 region induces the stress response of ubiquitin up to the translational level, leading to the rapid restoration of protein synthesis and to eventual neuronal survival.
 ...
PMID:Ubiquitin stress response in postischemic hippocampal neurons under nontolerant and tolerant conditions. 1041 29

We investigated early alterations in rat neurons after experimental ischemic stress. Transient ischemia was generated by bilateral occlusion of the carotids after hypoxia. Data show a relevant increase of the nuclear level of ubiquitin 2 h post-stress as evaluated by immuno-cytolocalization. Ubiquitin returns to normal levels after 6 h. The increase in ischemic/hypoxic rats was localized preferentially in nuclei of hippocampal neurons, although some augmentation was also shown essentially in dendrites. The activation of ubiquitin system is related to a defective homeostasis and might trigger different degenerative processes. With respect to this, we observed chromatin alterations by densitometric analysis. The shown extensive DNA degeneration is consistent with the occurrence of necrotic phenomena at an early stage. However the parallel internucleosomal specific DNA fragmentation, strongly suggests that apoptotic events also occur. In any case both necrosis and apoptosis are likely to occur at same time, although apoptosis is less extensive, and the two phenomena take place in different neural cells.
 ...
PMID:Acute ischemia/hypoxia in rat hippocampal neurons activates nuclear ubiquitin and alters both chromatin and DNA. 1296 45