Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
51
pubmed:dateCreated
2004-12-13
pubmed:abstractText
Cleavage of the beta-amyloid precursor protein (APP) by the aspartyl protease beta-site APP-cleaving enzyme (BACE) is the first step in the generation of the amyloid beta-peptide, which is deposited in the brain of Alzheimer's disease patients. Whereas the subsequent cleavage by gamma-secretase was shown to originate from the cooperation of a multicomponent complex, it is currently unknown whether in a cellular environment BACE is enzymatically active as a monomer or in concert with other proteins. Using blue native gel electrophoresis we found that endogenous and overexpressed BACE has a molecular mass of 140 kDa instead of the expected mass of 70 kDa under denaturing conditions. This suggests that under native conditions BACE exists as a homodimer. Homodimerization was confirmed by co-immunoprecipitation of full-length BACE carrying different epitope tags. In contrast, the soluble active BACE ectodomain was exclusively present as a monomer both under native and denaturing conditions. A domain analysis revealed that the BACE ectodomain dimerized as long as it was attached to the membrane, whereas the cytoplasmic domain and the transmembrane domain were dispensable for dimerization. By adding a KKXX-endoplasmic reticulum retention signal to BACE, we demonstrate that dimerization of BACE occurs already before full maturation and pro-peptide cleavage. Furthermore, kinetic analysis of the purified native BACE dimer revealed a higher affinity and turnover rate in comparison to the monomeric soluble BACE. Dimerization of BACE might, thus, facilitate binding and cleavage of physiological substrates.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
53205-12
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:15485862-Amino Acid Motifs, pubmed-meshheading:15485862-Amyloid Precursor Protein Secretases, pubmed-meshheading:15485862-Animals, pubmed-meshheading:15485862-Aspartic Acid Endopeptidases, pubmed-meshheading:15485862-Binding Sites, pubmed-meshheading:15485862-Catalysis, pubmed-meshheading:15485862-Cell Line, pubmed-meshheading:15485862-Cell Line, Tumor, pubmed-meshheading:15485862-Cell Membrane, pubmed-meshheading:15485862-Cell Movement, pubmed-meshheading:15485862-Chromatography, High Pressure Liquid, pubmed-meshheading:15485862-Cloning, Molecular, pubmed-meshheading:15485862-Cytoplasm, pubmed-meshheading:15485862-Dimerization, pubmed-meshheading:15485862-Dose-Response Relationship, Drug, pubmed-meshheading:15485862-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:15485862-Endopeptidases, pubmed-meshheading:15485862-Endoplasmic Reticulum, pubmed-meshheading:15485862-Epitopes, pubmed-meshheading:15485862-Humans, pubmed-meshheading:15485862-Immunoblotting, pubmed-meshheading:15485862-Immunoprecipitation, pubmed-meshheading:15485862-Kinetics, pubmed-meshheading:15485862-Mice, pubmed-meshheading:15485862-Microscopy, Fluorescence, pubmed-meshheading:15485862-Mutation, pubmed-meshheading:15485862-Protein Binding, pubmed-meshheading:15485862-Protein Structure, Tertiary, pubmed-meshheading:15485862-Transfection, pubmed-meshheading:15485862-Transgenes
pubmed:year
2004
pubmed:articleTitle
Dimerization of beta-site beta-amyloid precursor protein-cleaving enzyme.
pubmed:affiliation
Adolf Butenandt Institute, Department of Biochemistry, Laboratory for Alzheimer's and Parkinson's Disease Research, Schillerstrasse 44, Ludwig Maximilians University, 80336 Munich, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't