Mitochondrial Association of a Plus End–Directed Microtubule Motor Expressed during Mitosis in Drosophila

Abstract

The kinesin superfamily is a large group of proteins (kinesin-like proteins [KLPs]) that share sequence similarity with the microtubule (MT) motor kinesin. Several members of this superfamily have been implicated in various stages of mitosis and meiosis. Here we report our studies on KLP67A of Drosophila. DNA sequence analysis of KLP67A predicts an MT motor protein with an amino-terminal motor domain. To prove this directly, KLP67A expressed in Escherichia coli was shown in an in vitro motility assay to move MTs in the plus direction. We also report expression analyses at both the mRNA and protein level, which implicate KLP67A in the localization of mitochondria in undifferentiated cell types. In situ hybridization studies of the KLP67A mRNA during embryogenesis and larval central nervous system development indicate a proliferation-specific expression pattern. Furthermore, when affinity-purified anti-KLP67A antisera are used to stain blastoderm embryos, mitochondria in the region of the spindle asters are labeled. These data suggest that KLP67A is a mitotic motor of Drosophila that may have the unique role of positioning mitochondria near the spindle.

Symmetric and asymmetric mitotic segregation patterns influence Wolbachia distribution in host somatic tissue

“…Wolbachia might move using motors along astral microtubules, which continue to operate during Taxol treatment. This possibility is supported by studies suggesting that Wolbachia associate with microtubule plus-ends during spermatid elongation (Riparbelli and Callaini, 1998;Riparbelli et al, 2007), and via kinesin KLP67 on astral microtubules during early embryogenesis (Pereira et al, 1997). Another possibility is that Wolbachia only move on astral microtubules (see below).…”

Mitochondrial positioning in fission yeast is driven by association with dynamic microtubules and mitotic spindle poles

“…Previous studies have documented an association of mitochondria and other organelles with spindle aster microtubules in other species (19,20), but the functional significance of these associations has been unknown. Our results indicate that such an association provides one mechanism for the faithful segregation of mitochondria to opposite ends of the cell, ensuring inheritance of mitochondria by daughter cells.…”

A Drosophila Orthologue of Larp Protein Family Is Required for Multiple Processes in Male Meiosis

“…The mutant's phenotypes tell us that dLarp plays an essential role in this process, possibly working together with a plus-ended motor. As the Klp67A is known to be a functional Drosophila homologue of KIF1B that is a microtubule-based motor to transport mitochondria, this would be one of candidates involved in the transport of mitochondria (Pereira et al, 1997). The transition of mitochondria is thus regulated by an ordered mode rather than a stochastic partitioning strategy.…”