Current Biology
Volume 21, Issue 17, 13 September 2011, Pages 1431-1439
Journal home page for Current Biology

Article
mmb1p Binds Mitochondria to Dynamic Microtubules

https://doi.org/10.1016/j.cub.2011.07.013Get rights and content
Under an Elsevier user license
open archive

Summary

Background

Mitochondria form a dynamic tubular network within the cell. Proper mitochondria movement and distribution are critical for their localized function in cell metabolism, growth, and survival. In mammalian cells, mechanisms of mitochondria positioning appear dependent on the microtubule cytoskeleton, with kinesin or dynein motors carrying mitochondria as cargos and distributing them throughout the microtubule network. Interestingly, the timescale of microtubule dynamics occurs in seconds, and the timescale of mitochondria distribution occurs in minutes. How does the cell couple these two time constants?

Results

Fission yeast also relies on microtubules for mitochondria distribution. We report here a new microtubule-dependent but motor-independent mechanism for proper mitochondria positioning in fission yeast. We identify the protein mmb1p, which binds to mitochondria and microtubules. mmb1p attaches the tubular mitochondria to the microtubule lattice at multiple discrete interaction sites. mmb1 deletion causes mitochondria to aggregate, with the long-term consequence of defective mitochondria distribution and cell death. mmb1p decreases microtubule dynamicity.

Conclusions

mmb1p is a new microtubule-mitochondria binding protein. We propose that mmb1p acts to couple long-term mitochondria distribution to short-term microtubule dynamics by attenuating microtubule dynamics, thus enhancing the mitochondria-microtubule interaction time.

Highlights

► We report a new protein mmb1p in fission yeast ► mmb1p binds mitochondria to dynamic microtubules ► The absence of mmb1p leads to mitochondria aggregation and segregation defects ► mmb1p may be motor-independent mechanism for mitochondria distribution

Cited by (0)

3

Present address: Department of Biochemistry, University of Hong Kong, Hong Kong