Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.12.2 (MEK)
 18,161 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Examination of the expression of proteins linked with signaling pathways commanding cell death and cell survival has been carried out to increase understanding on the mechanisms leading to cell death in the cerebellum in Creutzfeldt-Jakob disease (CJD). Expression of Fas, Fas ligand (Fas-L), ERK, MEK, Bcl-2, Bax, N-myc, c-myc, pro-caspase-2 and active caspase-3 was examined by immunohistochemistry in the cerebellum of six patients with sporadic CJD, three patients with olivopontocerebellar atrophy (OPCA) and six age-matched controls. No modifications in the expression of these proteins were observed in granule cells in CJD and OPCA when compared with controls, except in a few cells in the molecular and granular layers in CJD that displayed dense homogeneous active caspase-3 immunostaining. This suggests selective activation of caspase-3 in association with increased cellular vulnerability in CJD. No modifications in pro-caspase-2 and c-myc immunoreactivity were observed in Purkinje cells in diseased brains when compared with controls. However, increased diffuse Fas, Fas-L, MEK, ERK and Bax expression, and enhanced granular active caspase-3 immunoreactivity was found in the cytoplasm of Purkinje cells in CJD. Increase in Bcl-2 and N-myc occurred in Purkinje cells in CJD and OPCA. These results indicate that enhanced Fas, Fas-L, MERK, ERK, Bax and granular active caspase-3 expression is not lethal to Purkinje cells in CJD, whereas increased Bcl-2 and N-myc does not preclude per se cell death or death survival in CJD and OPCA. These findings point to the likelihood that expression of these cell death proteins in neurodegeneration has functional roles differing from those related with apoptosis.
 ...
PMID:Cell death signaling in the cerebellum in Creutzfeldt-Jakob disease. 1158 44

Proteins containing the PB1 domain, a protein interaction module conserved in animals, fungi, amoebas, and plants, participate in diverse biological processes. The PB1 domains adopt a ubiquitin-like beta-grasp fold, containing two alpha helices and a mixed five-stranded beta sheet, and are classified into groups harboring an acidic OPCA motif (type I), the invariant lysine residue on the first beta strand (type II), or both (type I/II). The OPCA motif of a type I PB1 domain forms salt bridges with basic residues, especially the conserved lysine, of a type II PB1 domain, thereby mediating a specific PB1-PB1 heterodimerization, whereas additional contacts contribute to high affinity and specificity of the modular interaction. The canonical PB1 dimerization is required for the formation of complexes between p40(phox) and p67(phox) (for activation of the NADPH oxidase crucial for mammalian host defense), between the scaffold Bem1 and the guanine nucleotide exchange factor Cdc24 (for polarity establishment in yeasts), and between the polarity protein Par6 and atypical protein kinase C (for cell polarization in animal cells), as well as for the interaction between the mitogen-activated protein kinase kinase kinases MEKK2 or MEKK3 and the downstream target mitogen-activated protein kinase kinase MEK5 (for early cardiovascular development in mammals). PB1 domains can also mediate interactions with other protein domains. For example, an intramolecular interaction between the PB1 and PX domains of p40(phox) regulates phagosomal targeting of the microbicidal NADPH oxidase; the PB1 domain of MEK5 is likely responsible for binding to the downstream kinase ERK5, which lacks a PB1 domain; and the scaffold protein Nbr1 associates through a PB1-containing region with titin, a sarcomere protein without a PB1 domain. This Review describes various aspects of PB1 domains at the molecular and cellular levels.
 ...
PMID:Structure and function of the PB1 domain, a protein interaction module conserved in animals, fungi, amoebas, and plants. 1772 78