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Afadin: A Novel Actin Filament–binding Protein with One PDZ Domain Localized at Cadherin-based Cell-to-Cell Adherens Junction
- Source :
- The Journal of Cell Biology
- Publication Year :
- 1997
- Publisher :
- Rockefeller University Press, 1997.
-
Abstract
- A novel actin filament (F-actin)–binding protein with a molecular mass of ∼205 kD (p205), which was concentrated at cadherin-based cell-to-cell adherens junction (AJ), was isolated and characterized. p205 was purified from rat brain and its cDNA was cloned from a rat brain cDNA library. p205 was a protein of 1,829 amino acids (aa) with a calculated molecular mass of 207,667 kD. p205 had one F-actin–binding domain at 1,631–1,829 aa residues and one PDZ domain at 1,016– 1,100 aa residues, a domain known to interact with transmembrane proteins. p205 was copurified from rat brain with another protein with a molecular mass of 190 kD (p190). p190 was a protein of 1,663 aa with a calculated molecular mass of 188,971 kD. p190 was a splicing variant of p205 having one PDZ domain at 1,009–1,093 aa residues but lacking the F-actin–binding domain. Homology search analysis revealed that the aa sequence of p190 showed 90% identity over the entire sequence with the product of the AF-6 gene, which was found to be fused to the ALL-1 gene, known to be involved in acute leukemia. p190 is likely to be a rat counterpart of human AF-6 protein. p205 bound along the sides of F-actin but hardly showed the F-actin–cross-linking activity. Northern and Western blot analyses showed that p205 was ubiquitously expressed in all the rat tissues examined, whereas p190 was specifically expressed in brain. Immunofluorescence and immunoelectron microscopic studies revealed that p205 was concentrated at cadherin-based cell-to-cell AJ of various tissues. We named p205 l-afadin (a large splicing variant of AF-6 protein localized at adherens junction) and p190 s-afadin (a small splicing variant of l-afadin). These results suggest that l-afadin serves as a linker of the actin cytoskeleton to the plasma membrane at cell-to-cell AJ.
- Subjects :
- DNA, Complementary
Molecular Sequence Data
PDZ domain
Kinesins
Myosins
Biology
Peptide Mapping
Antibodies
Article
Adherens junction
Mice
Fetus
Cell Adhesion
Animals
Humans
Amino Acid Sequence
Cloning, Molecular
Peptide sequence
Integral membrane protein
Brain Chemistry
Cadherin
Microfilament Proteins
Brain
Chromosome Mapping
Cell Biology
Vinculin
Cadherins
Actin cytoskeleton
Molecular biology
Actins
Peptide Fragments
Recombinant Proteins
Rats
Cell biology
Molecular Weight
Intercellular Junctions
Actin filament binding
biology.protein
Spleen
Subjects
Details
- ISSN :
- 15408140 and 00219525
- Volume :
- 139
- Database :
- OpenAIRE
- Journal :
- Journal of Cell Biology
- Accession number :
- edsair.doi.dedup.....239bfe5d001acae5ca1bd71f13679998
- Full Text :
- https://doi.org/10.1083/jcb.139.2.517