Linked Life Data

19880378

Source:http://linkedlifedata.com/resource/pubmed/id/19880378

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2010-2-22
pubmed:abstractText
The complex of protein O-mannosyltransferase 1 (POMT1) and POMT2 catalyzes the initial step of O-mannosyl glycan biosynthesis. The mutations in either POMT1 or POMT2 can lead to Walker-Warburg syndrome, a congenital muscular dystrophy with abnormal neuronal migration. Here, we used three algorithms for predicting transmembrane helices to construct the secondary structural models of human POMT1 and POMT2. In these models, POMT1 and POMT2 have seven- and nine-transmembrane helices and contain four and five potential N-glycosylation sites, respectively. To determine whether these sites are actually glycosylated, we prepared mutant proteins that were defective in each site by site-directed mutagenesis. Three of the POMT1 sites and all of the POMT2 sites were found to be N-glycosylated, suggesting that these sites face the luminal side of the endoplasmic reticulum. Mutation of any single site did not significantly affect POMT activity, but mutations of all N-glycosylation sites of either POMT1 or POMT2 caused a loss of POMT activity. The loss of activity appeared to be due to the decreased hydrophilicity. These results suggest that the N-glycosylation of POMT1 and POMT2 is required for maintaining the conformation as well as the activity of the POMT1-POMT2 complex.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1756-2651
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
147
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
337-44
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:19880378-Amino Acid Sequence, pubmed-meshheading:19880378-Anti-Bacterial Agents, pubmed-meshheading:19880378-Cell Line, pubmed-meshheading:19880378-Endoplasmic Reticulum, pubmed-meshheading:19880378-Glycosylation, pubmed-meshheading:19880378-Humans, pubmed-meshheading:19880378-Hydrophobic and Hydrophilic Interactions, pubmed-meshheading:19880378-Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase, pubmed-meshheading:19880378-Mannosyltransferases, pubmed-meshheading:19880378-Models, Molecular, pubmed-meshheading:19880378-Molecular Sequence Data, pubmed-meshheading:19880378-Muscular Dystrophies, pubmed-meshheading:19880378-Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase, pubmed-meshheading:19880378-Polysaccharides, pubmed-meshheading:19880378-Protein Structure, Secondary, pubmed-meshheading:19880378-Solubility, pubmed-meshheading:19880378-Tunicamycin
pubmed:year
2010
pubmed:articleTitle
Role of N-glycans in maintaining the activity of protein O-mannosyltransferases POMT1 and POMT2.
pubmed:affiliation
Glycobiology Research Group, Tokyo Metropolitan Institute of Gerontology, Foundation for Research on Aging and Promotion of Human Welfare, 35-2 Sakaecho, Itabashi-ku, Tokyo, Japan. manya@tmig.or.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't