Histone acetylation affects many nuclear processes including transcription, chromatin assembly, and DNA damage repair. Acetylation of histone H3 lysine 56 (H3 K56ac) in budding yeast occurs during mitotic S phase and persists during DNA damage repair. Here, we show that H3 K56ac is also present during premeiotic S phase and is conserved in fission yeast. Furthermore, the H3 K56ac modification is not observed in the absence of the histone chaperone Asf1. asf1⌬ and H3 K56R mutants exhibit similar sensitivity to DNA damaging agents. Mutational analysis of Asf1 demonstrates that DNA damage sensitivity correlates with (i) decreased levels of H3 K56ac and (ii) a region implicated in histone binding. In contrast, multiple asf1 mutants that are resistant to DNA damage display WT levels of K56ac. These data suggest that maintenance of H3 K56 acetylation is a primary contribution of Asf1 to genome stability in yeast.chromatin assembly ͉ H3 K56ac ͉ DNA damage

This work describes the nature and sequence information content of the electron capture dissociation mass spectra for the intact Tetrahymena histone H2B. Two major variants of this protein were present bearing nominal modifications of both ؉42 and ؉84 Da. This work describes identification of the nature of these two modifications. For example, using gas-phase selection and isolation of the ؉42-Da modified species, from a background of two H2B variants each present in six or more posttranslationally modified isoforms, we were able to determine that this ؉42-Da modification isoform bears trimethylation rather than acetylation. LC-CIDMS analysis was also employed on digested preparations to obtain complementary detail of the nature of site-specific posttranslational modifications. This study establishes that integration of the information from these two datasets provides a comprehensive map of posttranslational occupancy for each particular covalent assemblage selected for structural investigation. Molecular & Cellular Proteomics 3: 872-886, 2004.

Our findings suggest that SedLine ® (machine)-generated indices might underestimate the minutes of EEG suppression, thereby reducing the sensitivity for detecting patients at risk for POD. Thus, the monitoring of machine-generated BSR and PSI™ might benefit from the addition of a visual tracing of the EEG to achieve a more accurate and real-time guidance of anaesthesia depth monitoring and the ultimate goal, to reduce the risk of POD.

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Objective: To study the relationship of the expression of phosphorylated cyclic AMP response element-binding protein (pCREB) and early growth response protein 1 (Egr1) in the hippocampus of aged mice with retrieval of consolidated spatial memory in a water maze. Methods: Twenty-four aged mice were allocated into no training or probe test (naïve), no training but exposed to the same probe test (NTPRT), received training and probe test (PRT), and received training but no probe test (NPRT) groups. Twelve mice were trained in a water maze over 14 days. After the final probe trial on day 15, all mice were anesthetized and the brains were removed. pCREB immunoreactivity (pCREB-ir) and Egr1 immunoreactivity (Egr1-ir) in the hippocampal CA1 and CA3 areas were examined. Results: pCREB-ir and Egr1-ir in the CA1 and CA3 areas of the NPRT and PRT groups were significantly higher than those of the naïve and NTPRT groups, and those in the PRT group were significantly higher than in the NPRT group. In all groups, pCREB-ir was significantly higher in the CA3 area compared to the CA1 area, while Egr1-ir was significantly higher in the CA1 area compared to the CA3 area. Conclusion: Retrieval, as well as formation, of consolidated spatial memory in the water maze is correlated with expression of pCREB and Egr1 in the hippocampus of aged mice.