The N-terminus of PrP is responsible for interacting with tubulin and fCJD related PrP mutants possess stronger inhibitive effect on microtubule assembly in vitro.
Microtubule dynamics is essential for many vital cellular processes such as in intracellular transport, metabolism, and cell division. Some evidences demonstrate that PrP may associate with microtubular cytoskeleton and its major component, tubulin. In the present study, the molecular interaction between PrP and tubulin was confirmed using pull-down assays, immunoprecipitation and ELISA. The interacting regions within PrP with tubulin were mapped in the N-terminus of PrP spanning residues 23-50 and 51-91. PrP octapeptide repeats are critical for the binding activity with tubulin, that the binding activity of PrP with tubulin became stronger along with the number of the octapeptide repeats increased. Microtubule assembly assays, sedimental tests and transmission electron microscopy demonstrated that the full-length PrP (aa 23-231) obviously inhibited the microtubule polymerization processes in vitro, whereas the N- (aa 23-91) and C- (aa 91-231) terminal peptides of PrP did not affect microtubule polymerization. Moreover, the familial Cruetzfeldt Jacob disease (fCJD) related PrP mutants with inserted or deleted octapeptide repeats showed much stronger inhibitive capacities on the microtubule dynamics in vitro than wild-type PrP. Our data highlight a potential role of PrP in regulating the microtubule dynamics in neurons.
State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Ying-Xin Road 100, Beijing 100052, People's Republic of China.
Chen-Fang
CF
Dong
Song
S
Shi
Xiao-Fan
XF
Wang
Run
R
An
Ping
P
Li
Jian-Ming
JM
Chen
Xin
X
Wang
Gui-Rong
GR
Wang
Bing
B
Shan
Bao-Yun
BY
Zhang
Jun
J
Han
Xiao-Ping
XP
Dong
D001665:Binding Sites; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D007562:Creutzfeldt-Jakob Syndrome / Q000378:metabolism*; D006801:Humans; D008870:Microtubules / Q000737:chemistry / Q000378:metabolism*; D009154:Mutation; D011328:Prions / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D013329:Structure-Activity Relationship; D014404:Tubulin / Q000737:chemistry / Q000378:metabolism*
D011328:Prions; D014404:Tubulin