Functionalities of cubic membranes

What are the functions, if any, of the cubic membranes It may be that cubic membranes are but an inevitable self-assembled product of the complex molecular soup of lipids and proteins the result of molecular packing considerations and inter-molecular interactions. This would be in analogy with known phase behaviour in equilibrium systems. Even though this is a very appealing solution to the long and unresolved debate about non-lamellar lipids in conjunction with cell membranes, we rather believe that these structural organisations have been chosen to fulfil a purpose (see, e.g. [134] and references therein for current theories, and [4] for a more comprehensive discussion), and the formation cannot be rationalised solely by molecular packing. 

Recognition of the existence of topologically distinct spaces through the formation of cubic membranes implies that cell space is restricted and predetermined, in the fashion outlined above. This h)rpothesis leads to many consequences. For example, an alternative mechanism for intracellular transport and orgaitisation has been suggested [56] which does not depend upon the formation of vesicles (outlined in Chapter 3), though that is not excluded. 

We stress that transportation vesicles are not necessarily excluded by these considerations. Rather, they need not be the sole biomoleciilar porters, alone 

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Cubic membranes can be involved in curvature-controlled activation of certain enzymes, as well as control of enzyme activity. It is tempting to suggest the latter as a general function of cubic membranes since proteins could conceivably be located at regular points in the lattice. This could enhance transport efficiency of both product and substrate. Such mechanisms are particularly well suited for mass cooperative synthesis, such as those... 

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