Author/Editor     Derganc, Jure; Mironov, Alexander A; Svetina, Saša
Title     Physical factors that affect the number and size of Golgi cisternae
Type     članek
Source     Traffic
Vol. and No.     , št. 7
Publication year     2006
Volume     str. 85-96
Language     eng
Abstract     Despite continual membrane reorganization in the Golgi complex, the number of cisternae in a Golgi stack is a stable parameter. The cisternal number is conserved within any given cell line and also after Golgi reassembly, e.g. following brefeldin-A-induced disruption. However, the factors that determine the cisternal number in a single Golgi stack remain to be fully determined. We propose a simple mechanical model of the Golgi stack and present a theoretical analysis of different physical factors that may affect the number of cisternae in a Golgi stack. The model takes into account the Golgi membrane bending elasticity, which is refated to the membrane curvature, and the adhesion, which holds the cisternae together. The analysis shows that the equilibrium configuration of the Golgi stack can be regarded as a balance between these two effects - the adhesion, which tends to increase the number of cisternae, is opposed by the membrane resistance to bending, which does not favor highly curved cisternal rims. The adhesion strength that is needed to hold together a typical stack is calculated. In addition, the model is used to analyze changes in the cisternal numbers as a controlled traffic wave enters a Golgi stack and increases the amount of the membrane in that stack.
Descriptors     GOLGI APPARATUS
MODELS, THEORETICAL
ELASTICITY
INTRACELLULAR MEMBRANES
LIPID BILAYERS
BIOMECHANICS