A mathematical model for the keratin cycle of assembly and disassembly

We formulate a mathematical model to study the in vivo keratin organization in terms of repartition of the keratin material between three different structural states: soluble proteins, filament precursors and filamentous state. The model describes a cycle of assembly and disassembly of keratin material. A generic nucleation function and structural stability of filament precursors are assumed. It is established that the three structural states always coexist and that the repartition of keratin material never exhibits any cyclic behaviour. Under some conditions, it is shown that the choice of the nucleation function does not affect the qualitative behaviour of the system. However, it might change the stable repartition of the keratin material in the cell.