Identification of a candidate human spectrin Src homology 3 domain-binding protein suggests a general mechanism of association of tyrosine kinases with the spectrin-based membrane skeleton.
Spectrin is a widely expressed protein with specific isoforms found in erythroid and nonerythroid cells. Spectrin contains an Src homology 3 (SH3) domain of unknown function. A cDNA encoding a candidate spectrin SH3 domain-binding protein was identified by interaction screening of a human brain expression library using the human erythroid ... spectrin (alphaI) SH3 domain as a bait. Five isoforms of the alphaI SH3 domain-binding protein mRNA were identified in human brain. Mapping of SH3 binding regions revealed the presence of two alphaI SH3 domain binding regions and one Abl-SH3 domain binding region. The gene encoding the candidate spectrin SH3 domain-binding protein has been located to human chromosome 10p11.2 --> p12. The gene belongs to a recently identified family of tyrosine kinase-binding proteins, and one of its isoforms is identical to e3B1, an eps8-binding protein (Biesova, Z., Piccoli, C., and Wong, W. T. (1997)Oncogene 14, 233-241). Overexpression of the green fluorescent protein fusion of the SH3 domain-binding protein in NIH3T3 cells resulted in cytoplasmic punctate fluorescence characteristic of the reticulovesicular system. This fluorescence pattern was similar to that obtained with the anti-human erythroid spectrin alphaI SigmaI/betaI SigmaI antibody in untransfected NIH3T3 cells; in addition, the anti-alphaI SigmaI/betaI SigmaI antibody also stained Golgi apparatus. Immunofluorescence obtained using antibodies against alphaI SigmaI/++betaI SigmaI spectrin and Abl tyrosine kinase but not against alphaII/betaII spectrin colocalized with the overexpressed green fluorescent protein-SH3-binding protein. Based on the conservation of the spectrin SH3 binding site within members of this protein family and published interactions, a general mechanism of interactions of tyrosine kinases with the spectrin-based membrane skeleton is proposed.
Mesh Terms:
3T3 Cells, Adaptor Proteins, Signal Transducing, Amino Acid Sequence, Animals, Base Sequence, Binding Sites, Carrier Proteins, Cell Membrane, Chromosome Mapping, Chromosomes, Human, Pair 10, Cytoskeletal Proteins, DNA, Complementary, Humans, Mice, Molecular Sequence Data, Protein-Tyrosine Kinases, Recombinant Fusion Proteins, Saccharomyces cerevisiae, Sequence Homology, Amino Acid, Spectrin, src Homology Domains
3T3 Cells, Adaptor Proteins, Signal Transducing, Amino Acid Sequence, Animals, Base Sequence, Binding Sites, Carrier Proteins, Cell Membrane, Chromosome Mapping, Chromosomes, Human, Pair 10, Cytoskeletal Proteins, DNA, Complementary, Humans, Mice, Molecular Sequence Data, Protein-Tyrosine Kinases, Recombinant Fusion Proteins, Saccharomyces cerevisiae, Sequence Homology, Amino Acid, Spectrin, src Homology Domains
J. Biol. Chem.
Date: May. 29, 1998
PubMed ID: 9593709
View in: Pubmed Google Scholar
Download Curated Data For This Publication
7345
Switch View:
- Interactions 4