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Spatiotemporal Analysis of Cytokinetic Events in Fission Yeast
11:19

Spatiotemporal Analysis of Cytokinetic Events in Fission Yeast

Published on: February 20, 2017

A fission yeast kinesin affects Golgi membrane recycling

S C Brazer1, H P Williams, T G Chappell

  • 1Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3200, USA.

Yeast (Chichester, England)
|January 21, 2000
PubMed

Insights

Kinesin heavy chain (KHC) Klp3 in fission yeast is essential for brefeldin A-induced Golgi-to-ER membrane transport. While not affecting other organelles, Klp3 plays a specific role in this BFA-induced recycling process.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Genetics

Background:

  • Kinesin heavy chain (KHC) proteins are motor proteins crucial for intracellular transport.
  • Understanding KHC functions in diverse organisms like yeast provides insights into fundamental cellular processes.
  • Schizosaccharomyces pombe serves as a model organism for studying microtubule-dependent transport.

Purpose of the Study:

  • To investigate the in vivo functions of the kinesin motor gene klp3(+) in Schizosaccharomyces pombe.
  • To determine the role of Klp3 in the distribution and transport of organelles, including the endoplasmic reticulum (ER), Golgi, and mitochondria.
  • To elucidate Klp3's involvement in membrane trafficking pathways, particularly brefeldin A (BFA)-induced Golgi-to-ER recycling.

Main Methods:

  • Gene identification and characterization of klp3(+) in S. pombe.
  • Indirect immunofluorescence using HA epitope-tagged Klp3 protein.
  • Generation and analysis of klp3 null mutant cells.
  • Microscopy to assess organelle distribution (ER, Golgi, mitochondria).
  • Treatment with drugs like latrunculin A, thiabendazole, and brefeldin A.
  • Visualization of endocytosis and vacuole dynamics using the vital dye FM4-64.

Main Results:

  • Klp3 exhibits homology to Neurospora crassa KHC and localizes to microtubule-associated cytoplasmic patches.
  • klp3 null mutants are viable, with normal distribution of ER, Golgi, and mitochondria.
  • Mitochondrial distribution is microtubule-dependent but not actin-dependent in S. pombe.
  • Endocytosis and vacuole dynamics are unaffected in klp3 null cells.
  • Klp3 plays a role in BFA-induced Golgi-to-ER membrane transport, with defective recycling observed in klp3 null cells.

Conclusions:

  • Klp3 is a functional kinesin motor protein in S. pombe.
  • While essential for BFA-induced Golgi-to-ER transport, Klp3 is not critical for general ER, Golgi, or mitochondrial distribution.
  • Mitochondrial distribution in fission yeast is primarily microtubule-dependent, unlike in budding yeast.
  • Klp3 has a specific role in regulating membrane trafficking pathways affected by brefeldin A.

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