Direct interaction between prion protein and tubulin

• Published in: Biochemical and biophysical research communications Vol. 334; no. 2; pp. 403 - 411
• Main Authors: Nieznanski, Krzysztof, Nieznanska, Hanna, Skowronek, Krzysztof J., Osiecka, Katarzyna M., Stepkowski, Dariusz
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 26.08.2005
• Subjects: Animals; Binding Sites; Complexes; Cross-linking; Humans; Microtubules; Molecular Weight; Multiprotein Complexes - analysis; Multiprotein Complexes - chemistry; Prion protein; Protein Binding; PrPC Proteins - analysis; PrPC Proteins - chemistry; Swine; Tubulin; Tubulin - analysis; Tubulin - chemistry; Tubulin; Prion protein; Cross-linking; Complexes; Microtubules
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2005.06.092

Recently published data show that the prion protein in its cellular form (PrP C) is a component of multimolecular complexes. In this report, zero-length cross-linking with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) allowed us to identify tubulin as one of the molecules interacting with PrP C in complexes observed in porcine brain extracts. We found that porcine brain tubulin added to these extracts can be cross-linked with PrP C. Moreover, we observed that the 34 kDa species identified previously as full-length diglycosylated prion protein co-purifies with tubulin. Cross-linking of PrP C species separated by Cu 2+-loaded immobilized metal affinity chromatography confirmed that only the full-length protein but not the N-terminally truncated form (C1) binds to tubulin. By means of EDC cross-linking and cosedimentation experiments, we also demonstrated a direct interaction of recombinant human PrP (rPrP) with tubulin. The stoichiometry of cosedimentation implies that rPrP molecules are able to bind both the α- and β-isoforms of tubulin composing microtubule. Furthermore, prion protein exhibits higher affinity for microtubules than for unpolymerized tubulin.