TY - JOUR
T1 - One-Dimensional Search Dynamics of Tumor Suppressor p53 Regulated by a Disordered C-Terminal Domain
AU - Murata, Agato
AU - Itoh, Yuji
AU - Mano, Eriko
AU - Kanbayashi, Saori
AU - Igarashi, Chihiro
AU - Takahashi, Hiroto
AU - Takahashi, Satoshi
AU - Kamagata, Kiyoto
N1 - Funding Information:
This work was supported in whole or part by MEXT/JSPS KAKENHI No. JP26840045 (to K.K.), No. JP24113701 (to K.K.), No. JP15H01625 (to K.K.), No. JP16K07313 (to K.K.), and No. JP25104007 (to S.T.); by a grant for Basic Science Research Projects from The Sumitomo Foundation (to K.K.); by a grant from the Takeda Science Foundation (to K.K.); and by the Foundation for Promotion of Material Science and Technology of Japan (to K.K.).
PY - 2017/6/6
Y1 - 2017/6/6
N2 - Tumor suppressor p53 slides along DNA and finds its target sequence in drastically different and changing cellular conditions. To elucidate how p53 maintains efficient target search at different concentrations of divalent cations such as Ca2+ and Mg2+, we prepared two mutants of p53, each possessing one of its two DNA-binding domains, the CoreTet mutant having the structured core domain plus the tetramerization (Tet) domain, and the TetCT mutant having Tet plus the disordered C-terminal domain. We investigated their equilibrium and kinetic dissociation from DNA and search dynamics along DNA at various [Mg2+]. Although binding of CoreTet to DNA becomes markedly weaker at higher [Mg2+], binding of TetCT depends slightly on [Mg2+]. Single-molecule fluorescence measurements revealed that the one-dimensional diffusion of CoreTet along DNA consists of fast and slow search modes, the ratio of which depends strongly on [Mg2+]. In contrast, diffusion of TetCT consisted of only the fast mode. The disordered C-terminal domain can associate with DNA irrespective of [Mg2+], and can maintain an equilibrium balance of the two search modes and the p53 search distance. These results suggest that p53 modulates the quaternary structure of the complex between p53 and DNA under different [Mg2+] and that it maintains the target search along DNA.
AB - Tumor suppressor p53 slides along DNA and finds its target sequence in drastically different and changing cellular conditions. To elucidate how p53 maintains efficient target search at different concentrations of divalent cations such as Ca2+ and Mg2+, we prepared two mutants of p53, each possessing one of its two DNA-binding domains, the CoreTet mutant having the structured core domain plus the tetramerization (Tet) domain, and the TetCT mutant having Tet plus the disordered C-terminal domain. We investigated their equilibrium and kinetic dissociation from DNA and search dynamics along DNA at various [Mg2+]. Although binding of CoreTet to DNA becomes markedly weaker at higher [Mg2+], binding of TetCT depends slightly on [Mg2+]. Single-molecule fluorescence measurements revealed that the one-dimensional diffusion of CoreTet along DNA consists of fast and slow search modes, the ratio of which depends strongly on [Mg2+]. In contrast, diffusion of TetCT consisted of only the fast mode. The disordered C-terminal domain can associate with DNA irrespective of [Mg2+], and can maintain an equilibrium balance of the two search modes and the p53 search distance. These results suggest that p53 modulates the quaternary structure of the complex between p53 and DNA under different [Mg2+] and that it maintains the target search along DNA.
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U2 - 10.1016/j.bpj.2017.04.038
DO - 10.1016/j.bpj.2017.04.038
M3 - Article
C2 - 28591603
AN - SCOPUS:85020307050
VL - 112
SP - 2301
EP - 2314
JO - Biophysical Journal
JF - Biophysical Journal
SN - 0006-3495
IS - 11
ER -