Microtubule sliding drives proplatelet elongation and is dependent on cytoplasmic dynein

Blood. 2015 Jan 29;125(5):860-8. doi: 10.1182/blood-2014-09-600858. Epub 2014 Nov 19.


Bone marrow megakaryocytes produce platelets by extending long cytoplasmic protrusions, designated proplatelets, into sinusoidal blood vessels. Although microtubules are known to regulate platelet production, the underlying mechanism of proplatelet elongation has yet to be resolved. Here we report that proplatelet formation is a process that can be divided into repetitive phases (extension, pause, and retraction), as revealed by differential interference contrast and fluorescence loss after photoconversion time-lapse microscopy. Furthermore, we show that microtubule sliding drives proplatelet elongation and is dependent on cytoplasmic dynein under static and physiological shear stress by using fluorescence recovery after photobleaching in proplatelets with fluorescence-tagged β1-tubulin. A refined understanding of the specific mechanisms regulating platelet production will yield strategies to treat patients with thrombocythemia or thrombocytopenia.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Platelets / cytology
  • Blood Platelets / metabolism*
  • Cell Differentiation
  • Cytoplasm / metabolism
  • Cytoplasmic Dyneins / genetics
  • Cytoplasmic Dyneins / metabolism*
  • Fluorescence Recovery After Photobleaching
  • Gene Expression
  • Mechanotransduction, Cellular
  • Megakaryocytes / cytology
  • Megakaryocytes / metabolism*
  • Mice
  • Microscopy, Interference
  • Microtubules / chemistry
  • Microtubules / metabolism*
  • Primary Cell Culture
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Stress, Mechanical
  • Thrombopoiesis / genetics
  • Tubulin / genetics
  • Tubulin / metabolism*


  • Recombinant Proteins
  • Tubulin
  • Cytoplasmic Dyneins