Microtubule-bundling activity of the centrosomal protein, Cep169, and its binding to microtubules.
CDK5RAP2 is a centrosomal protein that regulates the recruitment of a γ-tubulin ring complex (γ-TuRC) onto centrosomes and microtubules (MTs) dynamics as a member of MT plus-end-tracking proteins (+TIPs). In our previous report, we found mammalian Cep169 as a CDK5RAP2 binding partner, and Cep169 accumulates at the distal ends of MTs and centrosomes, and coincides with CDK5RAP2. Depletion of Cep169 induces MT depolymerization, indicating that Cep169 targets MT tips and regulates stability and dynamics of MTs. However, how Cep169 contributes to the stabilization of MT remains unclear. Here we show that Cep169 is able to stabilize MTs and induces formation of long MT bundles with intense acetylation of MTs with CDK5RAP2, when expressed at higher levels in U2OS cells. In addition, we demonstrated that Cep169 forms homodimers through its N-terminal domain and directly interacts with MTs through its C-terminal domain. Interestingly, Cep169 mutants, which lack each domains, completely abolished the activity, respectively. Therefore, Cep169 bundles MTs and induces solid structure of MTs by crosslinking each adjacent MTs as a homodimer.
Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Ohkubo, Tokyo 169-8555, Japan.
Yusuke
Y
Mori
Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Ohkubo, Tokyo 169-8555, Japan.
Yuki
Y
Taniyama
Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Ohkubo, Tokyo 169-8555, Japan.
Sayori
S
Tanaka
Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Ohkubo, Tokyo 169-8555, Japan.
Hiroki
H
Fukuchi
Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Ohkubo, Tokyo 169-8555, Japan. Electronic address: yterada@waseda.jp.
Yasuhiko
Y
Terada
D001665:Binding Sites; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D018385:Centrosome / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000378:metabolism; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D014404:Tubulin / Q000378:metabolism
C405929:CDK5RAP2 protein, human; D018797:Cell Cycle Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008869:Microtubule-Associated Proteins; C000606874:NCKAP5L protein, human; D009419:Nerve Tissue Proteins; D014404:Tubulin
+TIPs; CDK5RAP2; Centrosome; MAPs; Microtubule bundle