Linked Life Data

1670773

Source:http://linkedlifedata.com/resource/pubmed/id/1670773

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1991-2-12
pubmed:abstractText
Covalently cross-linked multimers of lipocortin I are shown to be present in human epidermoid carcinoma A431 cells treated with epidermal growth factor or the calcium ionophore A23187. This intracellular cross-linking of lipocortin I is suggested to be mediated by the action of tissue transglutaminase, a Ca2(+)-dependent protein cross-linking enzyme. Cross-linking of lipocortin I competes with proteolytic digestion of the protein, and pretreatment of the cells with inhibitors for calpain (Ca2(+)-dependent intracellular protease) markedly enhanced the cross-linking of lipocortin I. Cross-linked lipocortin I is shown to be present in the soluble fraction of A431 cells as well as in the particulate fraction; a 34-kDa fragment of lipocortin I was solubilized successfully by plasmin digestion of the latter fraction. Immunofluorescence microscopy using specific antilipocortin-I antibody showed that cross-linked lipocortin I forms an envelope-like structure, which is not extracted with [ethylenebis(oxyethylenenitrilo)]tetraacetic acid (EGTA) or Triton X-100. In vitro incubation of purified lipocortin I with tissue transglutaminase resulted in the formation of covalently cross-linked lipocortin I dimer, tetramer, and so on. Amine incorporation and cross-linking studies using lipocortin I and its N-terminal truncated derivatives indicated that the cross-linking site is localized within the plasmin-susceptible N-terminal 29 amino acids of lipocortin I. The cross-linking of lipocortin I is shown to be accelerated more than 10 times by the addition of phosphatidylserine vesicles, on which lipocortin I molecules are most likely aligned in a conformation suitable for cross-linking. Collectively, these findings suggest that an increase of intracellular calcium concentration results in the attachment of lipocortin I onto the plasma membrane phospholipids through the C-terminal domain of the molecule where the membrane-bound lipocortin I is cross-linked by the action of tissue transglutaminase through the N-terminal domain.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
266
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1101-8
pubmed:dateRevised
2005-11-17
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Calcium-induced intracellular cross-linking of lipocortin I by tissue transglutaminase in A431 cells. Augmentation by membrane phospholipids.
pubmed:affiliation
Department of Dermatology, Faculty of Medicine, Kyoto University, Japan.
pubmed:publicationType
Journal Article