Document Detail


The amino terminal lectin-like domain of thrombomodulin is required for constitutive endocytosis.
MedLine Citation:
PMID:  9002969     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Thrombomodulin (TM) is a multidomain protein that serves as a cofactor in a major natural anticoagulant system. To further characterize the structure-function of TM, we have transfected COS cells with different truncated forms of TM. In the first form, COS cells expressing TM that lacks the putative signal peptide (17 residues); the lectin-like, hydrophobic N-terminal domain (226 residues); and 12 residues of the first epidermal growth factor (EGF)-like repeat (COSdel.238 cells) were found to function normally with respect to TM transport to the cell surface and thrombin-dependent protein C activation. However, in contrast to wild-type TM, as visually studied by immunofluorescence and immunogold electron microscopy, the COSdel.238 cells did not constitutively internalize anti-TM-TM or thrombin-TM complexes. To identify the region responsible for mediating the endocytic process, deletant forms of TM lacking either the lectin-like region (residues 2-155) or the hydrophobic region of the N-terminal domain (residues 161-202) were expressed in COS cells (COSdel.2-155 and COSdel.161-202, respectively). Protein C cofactor activity was maintained in both cells. Although the COSdel.161-202 cells behaved similarly to wild-type TM-transfected cells, visual studies showed a lack of constitutive internalization of thrombin-TM or anti-TM-TM complexes in the COSdel.2-155 cells. We conclude that the lectin-like domain of human TM serves to regulate cell surface expression of TM via the endocytic route and therefore may also play a major physiologic role in controlling intracellular and extracellular accumulation of thrombin in a variety of biologic systems.
Authors:
E M Conway; S Pollefeyt; D Collen; M Steiner-Mosonyi
Related Documents :
7602619 - Evidence that secretase cleavage of cell surface alzheimer amyloid precursor occurs aft...
7761399 - Cell-surface-expressed t-cell antigen-receptor zeta chain is associated with the cytosk...
21289859 - Survivin-t34a: molecular mechanism and therapeutic potential.
2285799 - Oscillations in cell morphology and redox state.
19601759 - Quantification of cell response to polymeric composites using a two-dimensional gradien...
21190249 - Overexpression of gastrokine 1 in gastric cancer cells induces fas-mediated apoptosis.
6321249 - Loss of proviral sequences in rsv-transformed mouse tumour cells accompanied by the for...
8316249 - Identification of the activation-labile gene: a single point mutation in the human gluc...
17446389 - The mysteries of sexual identity. the germ cell's perspective.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Blood     Volume:  89     ISSN:  0006-4971     ISO Abbreviation:  Blood     Publication Date:  1997 Jan 
Date Detail:
Created Date:  1997-02-24     Completed Date:  1997-02-24     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7603509     Medline TA:  Blood     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  652-61     Citation Subset:  AIM; IM    
Affiliation:
Department of Medicine, University of Toronto, Ontario, Canada.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Amino Acid Sequence
Animals
COS Cells
Gene Transfer Techniques
Humans
Molecular Sequence Data
Peptide Mapping
Structure-Activity Relationship
Thrombomodulin / chemistry*,  physiology
Chemical
Reg. No./Substance:
0/Thrombomodulin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Primary non-Hodgkin's lymphoma of the intestine: high prevalence of Epstein-Barr virus in Mexican ly...
Next Document:  Formation of multinucleated giant cells in vitro is dependent on the stage of monocyte to macrophage...