Received 17 February 1992. Accepted 27 May 1992.
ISOLATION AND CHARACTERIZATION OF GOLGI FROM COCCOLITHUS PELAGICUS (PRYMNESIOPHYCEAE)1
Version of Record online: 26 OCT 2004
Journal of Phycology
Volume 28, Issue 5, pages 643–648, October 1992
How to Cite
Wainwright, I. M., Kwon, D.-K. and Gonzalez, E. (1992), ISOLATION AND CHARACTERIZATION OF GOLGI FROM COCCOLITHUS PELAGICUS (PRYMNESIOPHYCEAE). Journal of Phycology, 28: 643–648. doi: 10.1111/j.0022-3646.1992.00643.x
This research was supported by the Office of Naval Research Contract to E.G. We thank Prof. David J. Chapman for extremely valuable help with conditions for growing Coccolithus in culture and for reading and commenting on this manuscript. We are also grateful to Ms. Cecilia Aguilar Zacarias for her excellent technical contributions.
- Issue online: 26 OCT 2004
- Version of Record online: 26 OCT 2004
- Ca2+-stimulated ATPase;
- Coccolithus pelagicus;
- Golgi apparatus;
- organelle separation;
Cells of the marine alga Coccolithus pelagicus (Wal-lich)J. Schiller grown in axenic cultures were homogenized and fractionated. The distribution of organelle markers was assessed enzymatically after centrifugation through zonal, density, and flotation gradients made with sucrose, sorbitol, or Percoll. Mitochondria (1.19 g·cm-3) and chloroplasts (1.15 g·cm-3) were recovered in sucrose gradients at densities similar to those observed for higher plants and most algae. The position of endoplasmic reticulum and plasma membrane in the gradients was monitored by NADPH cytochrome c reductase and vanadate-sensitive Mg2+-ATPase, respectively. Higher plant Golgi markers, latent undine diphosphatase (UDPase) and glucan synthase I, were colocalized at a density range including two peaks of activity at 1.13–1.15 g·cm-3.
Bound calcium was associated with high density (1.15 g·cm-3) membranes. Ca2+-stimulated ATPase was found at high levels on membranes that did not coisolate with the latent UDPase-containing membranes. The Ca2+-stimulated ATPase, a possible participant during calcification, was associated with a chloroplast-enriched fraction in all the organelle separation systems. However, about 30% of the total activity was separated from both the chloroplasts and Golgi on 0–70% Percoll gradients containing 0.4 M sucrose. The possible relationship of the Golgi and the high-density organelle exhibiting Ca2+-stimulated ATPase to coccolithogenesis and the process of calcification and crystal formation is discussed.