title: Non-erythroid beta spectrin interacting proteins and their effects on spectrin tetramerization.
abstract: With yeast two-hybrid methods, we used a C-terminal fragment (residues 1697-2145) of non-erythroid beta spectrin (βII-C), including the region involved in the association with alpha spectrin to form tetramers, as the bait to screen a human brain cDNA library to identify proteins interacting with βII-C. We applied stringent selection steps to eliminate false positives and identified 17 proteins that interacted with βII-C (IP(βII-C) s). The proteins include a fragment (residues 38-284) of "THAP domain containing, apoptosis associated protein 3, isoform CRA g", "glioma tumor suppressor candidate region gene 2" (residues 1-478), a fragment (residues 74-442) of septin 8 isoform c, a fragment (residues 704-953) of "coatomer protein complex, subunit beta 1, a fragment (residues 146-614) of zinc-finger protein 251, and a fragment (residues 284-435) of syntaxin binding protein 1. We used yeast three-hybrid system to determine the effects of these βII-C interacting proteins as well as of 7 proteins previously identified to interact with the tetramerization region of non-erythroid alpha spectrin (IP(αII-N) s) [1] on spectrin tetramer formation. The results showed that 3 IP(βII-C) s were able to bind βII-C even in the presence of αII-N, and 4 IP(αII-N) s were able to bind αII-N in the presence of βII-C. We also found that the syntaxin binding protein 1 fragment abolished αII-N and βII-C interaction, suggesting that this protein may inhibit or regulate non-erythroid spectrin tetramer formation.
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor Street, MC 111, Chicago, IL 60607, USA.
authors.forename: Akin
authors.initials: A
authors.lastname: Sevinc
authors.forename: Leslie W-M
authors.initials: LW
authors.lastname: Fung
mesh_terms: D001665:Binding Sites; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D003599:Cytoskeleton / Q000737:chemistry / Q000378:metabolism*; D015723:Gene Library; D006801:Humans; D008840:Microfilament Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids; D058105:Polymerization; D011485:Protein Binding; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D020798:Two-Hybrid System Techniques; D013049:Spectrin
chemical_list: D002352:Carrier Proteins; D008840:Microfilament Proteins; D010446:Peptide Fragments; D020033:Protein Isoforms; D011994:Recombinant Proteins; D013049:Spectrin