The role of the extracellular domain in the biology of the coxsackievirus and adenovirus receptor.
Am J Respir Cell Mol Biol
; 32(6): 498-503, 2005 Jun.
Article
in En
| MEDLINE
| ID: mdl-15778494
ABSTRACT
The Coxsackievirus B and Adenovirus Receptor (CAR) plays a dual role as a homotypic junctional adhesion protein and as a viral receptor. CAR is a transmembrane protein and a member of the Immunoglobulin (Ig) superfamily with two extracellular Ig-like domains. The most distal Ig-like domain (D1) mediates the homophilic interaction and is also responsible for the high-affinity binding of the adenovirus (Ad) fiber protein. Currently, no activity has been ascribed to the proximal Ig-like domain (D2). To further understand the function of the extracellular domain in the biological activities of CAR, we created extracellular deletion mutants and evaluated cellular localization, adhesion, and viral infection. Deletion of any segment of the extracellular domain results in loss of adhesion and mislocalization as explained by a model, termed "diffusion trapping," that suggests adhesion is the driving force in junctional localization. Loss of junctional localization and adhesion was particularly apparent in polarized human airway epithelia, where mutant CAR expression was basolateral but not limited to the lateral junctions between cells. Surprisingly, the D2 domain was required for adenovirus fiber-knob binding and infection. In summary, the entire extracellular domain of CAR is of vital importance to the biology of this highly conserved and important protein.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Receptors, Virus
/
Respiratory Mucosa
Type of study:
Prognostic_studies
Limits:
Animals
/
Humans
Language:
En
Journal:
Am J Respir Cell Mol Biol
Journal subject:
BIOLOGIA MOLECULAR
Year:
2005
Document type:
Article
Affiliation country:
United States