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 (?II-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 ?II-C. We applied stringent selection steps to eliminate false positives and identified 17 proteins that interacted with ?II-C (IP(?II-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 ?II-C interacting proteins as well as of 7 proteins previously identified to interact with the tetramerization region of non-erythroid alpha spectrin (IP(?II-N) s) [1] on spectrin tetramer formation. The results showed that 3 IP(?II-C) s were able to bind ?II-C even in the presence of ?II-N, and 4 IP(?II-N) s were able to bind ?II-N in the presence of ?II-C. We also found that the syntaxin binding protein 1 fragment abolished ?II-N and ?II-C interaction, suggesting that this protein may inhibit or regulate non-erythroid spectrin tetramer formation.

SUBMITTER: Sevinc A 

PROVIDER: S-EPMC3675649 | biostudies-other | 2011 Dec

REPOSITORIES: biostudies-other