Interaction of junctional adhesion molecule with the tight junction components ZO-1, cingulin, and occludin.
Junctional adhesion molecule (JAM) is an integral membrane protein that has been reported to colocalize with the tight junction molecules occludin, ZO-1, and cingulin. However, evidence for the association of JAM with these molecules is missing. Transfection of Chinese hamster ovary cells with JAM (either alone or in combination with occludin) resulted in enhanced junctional localization of both endogenous ZO-1 and cotransfected occludin. Additionally, JAM was coprecipitated with ZO-1 in the detergent-insoluble fraction of Caco-2 epithelial cells. A putative PDZ-binding motif at the cytoplasmic carboxyl terminus of JAM was required for mediating the interaction of JAM with ZO-1, as assessed by in vitro binding and coprecipitation experiments. JAM was also coprecipitated with cingulin, another cytoplasmic component of tight junctions, and this association required the amino-terminal globular head of cingulin. Taken together, these data indicate that JAM is a component of the multiprotein complex of tight junctions, which may facilitate junction assembly.
Bazzoni
G
G
Istituto di Ricerche Farmacologiche Mario Negri, 20157 Milano, Italy. bazzoni@irfmn.mnegri.it
Martinez-Estrada
O M
OM
Orsenigo
F
F
Cordenonsi
M
M
Citi
S
S
Dejana
E
E
D000818:Animals; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D006801:Humans; D062726:Junctional Adhesion Molecules; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008840:Microfilament Proteins; D008856:Microscopy, Fluorescence; D046912:Multiprotein Complexes; D062793:Occludin; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D011233:Precipitin Tests; D011485:Protein Binding; D019108:Tight Junctions / Q000378:metabolism*; D014162:Transfection; D062826:Zonula Occludens-1 Protein
C061407:CGN protein, human; D015815:Cell Adhesion Molecules; D062726:Junctional Adhesion Molecules; D046911:Macromolecular Substances; D008565:Membrane Proteins; D008840:Microfilament Proteins; D046912:Multiprotein Complexes; C568985:OCLN protein, human; D062793:Occludin; D010750:Phosphoproteins; C569042:TJP1 protein, human; D062826:Zonula Occludens-1 Protein