TY - JOUR
T1 - Soluble tubulin is significantly enriched at mitotic centrosomes
AU - Baumgart, Johannes
AU - Kirchner, Marcel
AU - Redemann, Stefanie
AU - Bond, Alec
AU - Woodruff, Jeffrey
AU - Verbavatz, Jean Marc
AU - Jülicher, Frank
AU - Müller-Reichert, Thomas
AU - Hyman, Anthony A.
AU - Brugués, Jan
N1 - Publisher Copyright:
© 2019 Baumgart et al.
PY - 2019/12/2
Y1 - 2019/12/2
N2 - During mitosis, the centrosome expands its capacity to nucleate microtubules. Understanding the mechanisms of centrosomal microtubule nucleation is, however, constrained by a lack of knowledge of the amount of soluble and polymeric tubulin at mitotic centrosomes. Here we combined light microscopy and serial-section electron tomography to measure the amount of dimeric and polymeric tubulin at mitotic centrosomes in early C. elegans embryos. We show that a C. elegans one-cell stage centrosome at metaphase contains >10,000 microtubules with a total polymer concentration of 230 µM. Centrosomes concentrate soluble α/β tubulin by about 10-fold over the cytoplasm, reaching peak values of 470 µM, giving a combined total monomer and polymer tubulin concentration at centrosomes of up to 660 µM. These findings support in vitro data suggesting that microtubule nucleation in C. elegans centrosomes is driven in part by concentrating soluble tubulin.
AB - During mitosis, the centrosome expands its capacity to nucleate microtubules. Understanding the mechanisms of centrosomal microtubule nucleation is, however, constrained by a lack of knowledge of the amount of soluble and polymeric tubulin at mitotic centrosomes. Here we combined light microscopy and serial-section electron tomography to measure the amount of dimeric and polymeric tubulin at mitotic centrosomes in early C. elegans embryos. We show that a C. elegans one-cell stage centrosome at metaphase contains >10,000 microtubules with a total polymer concentration of 230 µM. Centrosomes concentrate soluble α/β tubulin by about 10-fold over the cytoplasm, reaching peak values of 470 µM, giving a combined total monomer and polymer tubulin concentration at centrosomes of up to 660 µM. These findings support in vitro data suggesting that microtubule nucleation in C. elegans centrosomes is driven in part by concentrating soluble tubulin.
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U2 - 10.1083/JCB.201902069
DO - 10.1083/JCB.201902069
M3 - Article
C2 - 31636117
AN - SCOPUS:85075960562
SN - 0021-9525
VL - 218
SP - 3977
EP - 3985
JO - Journal of Cell Biology
JF - Journal of Cell Biology
IS - 12
ER -