QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Vol. 16, Issue 5, 2493-2502, May 2005

This Article Full Text Full Text (PDF) All Versions of this Article: E05-01-0068v1 16/5/2493    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nishida, K. Articles by Kuroiwa, T. Search for Related Content PubMed PubMed Citation Articles by Nishida, K. Articles by Kuroiwa, T.

Cell Cycle-regulated, Microtubule-independent Organelle Division in Cyanidioschyzon merolae

Keiji Nishida ^* , Fumi Yagisawa ^* , Haruko Kuroiwa ^*, Toshiyuki Nagata , and Tsuneyoshi Kuroiwa ^*

^* Department of Life Science, College of Science, Rikkyo University, Tokyo, 171-8501 Japan; Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, 113-0033 Japan

Submitted January 25, 2005; Revised February 28, 2005; Accepted March 1, 2005
Monitoring Editor: Thomas Fox

Mitochondrial and chloroplast division controls the number and morphology of organelles, but how cells regulate organelle division remains to be clarified. Here, we show that each step of mitochondrial and chloroplast division is closely associated with the cell cycle in Cyanidioschyzon merolae. Electron microscopy revealed direct associations between the spindle pole bodies and mitochondria, suggesting that mitochondrial distribution is physically coupled with mitosis. Interconnected organelles were fractionated under microtubule-stabilizing condition. Immunoblotting analysis revealed that the protein levels required for organelle division increased before microtubule changes upon cell division, indicating that regulation of protein expression for organelle division is distinct from that of cytokinesis. At the mitochondrial division site, dynamin stuck to one of the divided mitochondria and was spatially associated with the tip of a microtubule stretching from the other one. Inhibition of microtubule organization, proteasome activity or DNA synthesis, respectively, induced arrested cells with divided but shrunk mitochondria, with divided and segregated mitochondria, or with incomplete mitochondrial division restrained at the final severance, and repetitive chloroplast division. The results indicated that mitochondrial morphology and segregation but not division depend on microtubules and implied that the division processes of the two organelles are regulated at distinct checkpoints.

Address correspondence to: Keiji Nishida (z2002378{at}rikkyo.ne.jp).

This article has been cited by other articles:

				J. Gillard, V. Devos, M. J.J. Huysman, L. De Veylder, S. D'Hondt, C. Martens, P. Vanormelingen, K. Vannerum, K. Sabbe, V. A. Chepurnov, et al. Physiological and Transcriptomic Evidence for a Close Coupling between Chloroplast Ontogeny and Cell Cycle Progression in the Pennate Diatom Seminavis robusta Plant Physiology, November 1, 2008; 148(3): 1394 - 1411. [Abstract] [Full Text] [PDF]

				M. Ohnuma, T. Yokoyama, T. Inouye, Y. Sekine, and K. Tanaka Polyethylene Glycol (PEG)-Mediated Transient Gene Expression in a Red Alga, Cyanidioschyzon merolae 10D Plant Cell Physiol., January 1, 2008; 49(1): 117 - 120. [Abstract] [Full Text] [PDF]

				K. Nishida, F. Yagisawa, H. Kuroiwa, Y. Yoshida, and T. Kuroiwa WD40 protein Mda1 is purified with Dnm1 and forms a dividing ring for mitochondria before Dnm1 in Cyanidioschyzon merolae PNAS, March 13, 2007; 104(11): 4736 - 4741. [Abstract] [Full Text] [PDF]

				E. Lopez-Juez Plastid biogenesis, between light and shadows J. Exp. Bot., January 1, 2007; 58(1): 11 - 26. [Abstract] [Full Text] [PDF]