Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.4.21.7 (
plasmin
)
9,023
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
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.
...
PMID:Calcium-induced intracellular cross-linking of lipocortin I by tissue transglutaminase in A431 cells. Augmentation by membrane phospholipids. 167 Jul 73
