HKUST Institutional Repository >
BIOL Journal/Magazine Articles >
Please use this identifier to cite or link to this item:
|Title: ||Dynamic redistribution of calmodulin in HeLa cells during cell division as revealed by a GFP-calmodulin fusion protein technique|
|Authors: ||Li, Chao-Jun|
Tsien, Roger Y.
Chang, Donald C.
GFP-calmodulin fusion protein technique
|Issue Date: ||1999 |
|Citation: ||Journal of cell science, v. 112, no. 10, May 1999, p. 1567-1577|
|Abstract: ||It has been suggested by many studies that Ca2+ signaling plays an important role in regulating key steps in cell division. In order to study the down stream components of calcium signaling, we have fused the gene of calmodulin (CaM) with that of green fluorescent protein (GFP) and expressed it in HeLa cells. The GFP-CaM protein was found to have similar biochemical properties as the wildtype CaM, and its distribution was also similar to that of the endogenous CaM. Using this GFP-tagged CaM as a probe, we have conducted a detailed examination of the spatial- and temporal-dependent redistribution of calmodulin in living mammalian cells during cell division. Our major findings are: (1) high density of CaM was found to distribute in two sub-cellular locations during mitosis; one fraction was concentrated in the spindle poles, while the other was concentrated in the sub-membrane region around the cell. (2) The sub-membrane fraction of CaM became aggregated at the equatorial region where the cleavage furrow was about to form. The timing of this localized aggregation of CaM was closely associated with the onset of cytokinesis. (3) Using a TA-CaM probe, we found that the sub-membrane fraction of CaM near the cleavage furrow was selectively activated during cell division. (4) When we injected a CaM-specific inhibitory peptide into early anaphase cells, cytokinesis was either blocked or severely delayed. These findings suggest that, in addition to Ca2+ ion, CaM may represent a second signal that can also play an active role in determining the positioning and timing of the cleavage furrow formation.|
|Rights: ||Permission is granted by the Company of Biologists Ltd. The paper was published in J Cell Sci 1999 112 : 1567-1577.|
|Appears in Collections:||BIOL Journal/Magazine Articles|
Files in This Item:
All items in this Repository are protected by copyright, with all rights reserved.