|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
Research Article |
Cancer Research Campaign Cell Cycle Genetics Group, University of Cambridge, Department of Genetics, Downing Street, Cambridge CB2 3EH, UK
* Author for correspondence (e-mail: dmg25{at}mole.bio.cam.ac.uk )
Accepted 12 November 2001
The kinesin-like protein encoded by pavarotti (Pav-KLP) is essential for cytokinesis and associates with the central part of the late mitotic spindle and interphase nuclei in somatic cells (Adams et al., 1988). Here we define regions of the molecule that regulate its subcellular localisation and study the consequences of overexpressing mutant forms of the protein during oogenesis in Drosophila. Pav-KLP normally associates with the oocyte nucleus, but when over-expressed at moderate levels, its GFP tagged form also accumulates in nurse cell nuclei. At high expression levels this leads to loss of the microfilaments that tether these nuclei, so that they block the ring canals and prevent the `dumping' of nurse cell cytoplasm into the oocyte, which results in sterility. Localisation to these nuclei is prevented by mutations in either the conserved ATP-binding site of the motor domain or the nuclear localisation sequences in the C-terminal domain. Both such mutations lead to the formation of stable arrays of cytoplasmic microtubules and the progressive disruption of the actin cytoskeleton. The latter is evident by a breakdown of the cortical actin causing disruption of cell membranes; this breakdown ultimately results in the accumulation of cytoplasmic aggregates containing tubulin, actin and at least some of their binding proteins. Pav-KLP is also found associated with the ring canals, actin-rich structures built from remnants of the cytokinesis ring. The stalk domain alone is sufficient for the exclusive association of Pav-KLP to these structures, and this has no consequences for fertility. We discuss whether disruption of actin structures by full-length cytoplasmic forms of Pav-KLP is a consequence of the resulting stabilised cytoplasmic microtubules per se or accumulation of the motor protein at ectopic cortical sites to sequester molecules that regulate actin behaviour.
Key words: Pavarotti, MKLP-1, Actinomyosin, Drosophila oogenesis, Contractile rings
This article has been cited by other articles:
![]() |
J. K. Jang, T. Rahman, V. S. Kober, J. Cesario, and K. S. McKim Misregulation of the Kinesin-like Protein Subito Induces Meiotic Spindle Formation in the Absence of Chromosomes and Centrosomes Genetics, September 1, 2007; 177(1): 267 - 280. [Abstract] [Full Text] [PDF] |
||||
![]() |
J.-G. Delcros, C. Prigent, and R. Giet Dynactin targets Pavarotti-KLP to the central spindle during anaphase and facilitates cytokinesis in Drosophila S2 cells J. Cell Sci., November 1, 2006; 119(21): 4431 - 4441. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. K. Jang, T. Rahman, and K. S. McKim The Kinesinlike Protein Subito Contributes to Central Spindle Assembly and Organization of the Meiotic Spindle in Drosophila Oocytes Mol. Biol. Cell, October 1, 2005; 16(10): 4684 - 4694. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Goshima and R. D. Vale Cell Cycle-dependent Dynamics and Regulation of Mitotic Kinesins in Drosophila S2 Cells Mol. Biol. Cell, August 1, 2005; 16(8): 3896 - 3907. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Y. N. Goldstein, Y.-N. Jan, and L. Luo Function and regulation of Tumbleweed (RacGAP50C) in neuroblast proliferation and neuronal morphogenesis PNAS, March 8, 2005; 102(10): 3834 - 3839. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. H. Inoue, M. S. Savoian, T. Suzuki, E. Mathe, M.-T. Yamamoto, and D. M. Glover Mutations in orbit/mast reveal that the central spindle is comprised of two microtubule populations, those that initiate cleavage and those that propagate furrow ingression J. Cell Biol., July 5, 2004; 166(1): 49 - 60. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. P. D'Avino, M. S. Savoian, and D. M. Glover Mutations in sticky lead to defective organization of the contractile ring during cytokinesis and are enhanced by Rho and suppressed by Rac J. Cell Biol., July 5, 2004; 166(1): 61 - 71. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Liu, T. Zhou, R. Kuriyama, and R. L. Erikson Molecular interactions of Polo-like-kinase 1 with the mitotic kinesin-like protein CHO1/MKLP-1 J. Cell Sci., July 1, 2004; 117(15): 3233 - 3246. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Glotzer Cleavage furrow positioning J. Cell Biol., February 2, 2004; 164(3): 347 - 351. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Minestrini, A. S. Harley, and D. M. Glover Localization of Pavarotti-KLP in Living Drosophila Embryos Suggests Roles in Reorganizing the Cortical Cytoskeleton during the Mitotic Cycle Mol. Biol. Cell, October 1, 2003; 14(10): 4028 - 4038. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Mathe, Y. H. Inoue, W. Palframan, G. Brown, and D. M. Glover Orbit/Mast, the CLASP orthologue of Drosophila, is required for asymmetric stem cell and cystocyte divisions and development of the polarised microtubule network that interconnects oocyte and nurse cells during oogenesis Development, March 1, 2003; 130(5): 901 - 915. [Abstract] [Full Text] [PDF] |
||||