Exocrine gland tight junction-constituting protein jeap family
A mouse cDNA library from gene fragments encoding proteins localizing at cell-cell junctions was screened by a technique visualizing localization of a protein to to identify a junction-enriched and -associated protein, JEAP. GenBank homology search was performed based on the sequence. Based on the obtained sequence, a mouse cDNA library was screened to identify JEAP-2. By using prepared antibodies against these proteins, it was revealed that these proteins express specifically at tight junctions, in particular, tight junctions in exocrine glands.
1. An isolated DNA encoding a protein of the following (a) or (b):
(a) a protein having an amino acid sequence shown in SEQ ID NO:4; and
(b) a protein having an amino acid sequence having deletion, substitution or addition of a single amino acid in an amino acid sequence shown in SEQ ID NO:2 or SEQ ID NO:4, and localizing at tight junctions, with a proviso that the protein is not a protein having an amino acid sequence shown in SEQ ID NO:2.
2. An isolated DNA according to claim 1 , having a nucleotide sequence shown in SEQ ID NO:3.
3. A recombinant vector comprising the DNA as defined in claim 1 .
4. A transformant obtained by transforming a host with the DNA as defined in a claim 1 .
5. A method for producing a protein localizing at tight junctions, comprising:
culturing the transformant as defined in claim 4 ; and
collecting a protein localizing at tight junctions expressed by the transformant from the culture.
6. A recombinant vector comprising the DNA as defined in claim 2 .
7. A transformant obtained by transforming a host with the DNA as defined in claim 2 .
8. A method for producing a protein localizing at tight junctions, comprising:
culturing the transformant as defined in claim 7 ; and
collecting a protein localizing at tight junctions expressed by the transformant from the culture.