Mixed-lineage kinase 3 (MLK3) is a mitogen-activated protein kinase (MAPK) kinase kinase that activates MAPK pathways, including the c-Jun NH(2)-terminal kinase (JNK) and p38 pathways. MLK3 and its family members have been implicated in JNK-mediated apoptosis. A survey of human cell lines revealed high levels of MLK3 in breast cancer cells. To learn more about MLK3 regulation and its signaling ...

In order to define the mechanisms responsible for the regulated expression of a human 90-kDa heat shock protein (HSP90) gene, we have determined the complete genomic sequence of the gene encoding HSP90 beta, including 1102 base pairs upstream of the transcription initiation site. This gene consists of 12 exons and 11 introns. The exons range in size from 99 to 396 base pairs and the introns ran...

Vaso-occlusive events are the major source of morbidity and mortality in sickle cell disease (SCD); however, the pathogenic mechanisms driving these events remain unclear. Using hypoxia to induce pulmonary injury, we investigated mechanisms by which sickle hemoglobin increases susceptibility to lung injury in a murine model of SCD, where mice either exclusively express the human alpha/sickle be...

Aim: The aim of this study was to investigate heat shock protein 90 (HSP90) and topoisomerase I (Topo I) expression the association between both proteins clinicopathological parameters colorectal cancer (CRC), in order describe their role tumor biology regarding Kirsten Ras (KRAS) – positive/negative cases. Materials Methods: Expression HSP90 Topo I, KRAS gene mutations were estimated primary C...

PURPOSE Most gastrointestinal stromal tumors harbor a mutated KIT or PDGFRA receptor tyrosine kinase (RTK). Heat shock protein 90 (Hsp90) is a chaperone mediating the folding and stabilization of many oncoproteins, including KIT. An Hsp90 inhibitor, 17-AAG, can attenuate KIT activation and proliferation of gastrointestinal stromal tumor cell lines. We further evaluated Hsp90 immunoexpression an...

Lipid peroxidation during oxidative stress leads to increased concentrations of thiol-reactive alpha,beta-unsaturated aldehyde, including 4-hydroxy-2-nonenal (4-HNE) and 4-oxo-2-nonenal (4-ONE). These aldehydes have a documented ability to disrupt protein function following adduct formation with specific residues. Therefore, to identify 4-HNE-modified proteins in a model of ethanol-induced oxid...

The molecular chaperone Hsp90 depends upon large conformational rearrangements for its function. One driving force for these rearrangements is the intrinsic ATPase activity of Hsp90, as seen with other chaperones. However, unlike other chaperones, structural and kinetic studies have shown that the ATPase cycle of Hsp90 is not conformationally deterministic. That is, rather than dictating the co...

Functional changes in chaperone systems play a major role the decline of cognition and contribute to neurological pathologies, such as Alzheimer’s disease (AD). While may occur naturally with age or stress trauma, mechanisms involved have remained elusive. The current models suggest that amyloid-β (Aβ) plaque formation leads hyperphosphorylation tau by Hsp90-dependent process triggers neurofibr...

The accumulation of misfolded proteins in the human brain is one of the critical features of many neurodegenerative diseases, including Alzheimer's disease (AD). Assembles of beta-amyloid (Aβ) peptide-either soluble (oligomers) or insoluble (plaques) and of tau protein, which form neurofibrillary tangles, are the major hallmarks of AD. Chaperones and co-chaperones regulate protein folding and c...