The residues of these motives transform the chemical energy derived from ATP hydrolysis into a mechanical force necessary for helicase movements for the disruption of ssRNA or RNA base pairs.
These observations are consistent with a model in which F-actin dynamics are needed in the invagination stage of endocytosis to provide the mechanical force necessary to overcome osmotic pressure in yeast, something not quite relevant to mammalian cells.
In the Aquiflex aeolicus PilT structure (Satyshur et al, 2007), it was proposed that a 15 Å movement of the C-terminal domain observed upon nucleotide hydrolysis and γ-phosphate release would be sufficient to provide the mechanical force necessary to extract pilin subunits from the pilus during disassembly.
Probable reasons include the lack of mechanical forces and dynamic flow system that provide necessary mechanistic signals and continuous supply and/or drainage of nutrients and metabolites.
We first established by IFA the existence of a bridge between AMA1 and RON2 at the host cell interface during invasion, and provide direct evidence that an optimal AMA1 RON2 interaction is necessary to withstand the sheering mechanical forces involved in host cell invasion, a result already suggested by our previous structural analysis12,13.
A common element in both processes is the presence of mechanical forces acting along the fiber axis, which are necessary in both cases to expose self-association sites in individual fibronectin molecules and possibly align the molecules as they assemble into fibrils.
A better understanding of the micromechanical properties of extramacular hair bundles would be necessary to evaluate the significance of mechanical forces exerted by extramacular kinocilia following efferent stimulation.
In fact, the determination of how mechanical forces can be utilized is a challenge for bioreactor design in order to reach the proper environment necessary to produce the desired tissue engineered product.
Many different methods have been realized that rely on a variety of approaches how to create the necessary forces, such as optical radiation forces, electric forces (dielectrophoresis), magnetic forces (magnetic tweezers) or mechanical forces generated by sound waves (for reviews see [ 1, 2, 3, 4, 5, 6]).
It is necessary to collect the information of mechanical force distribution at different levels, and map the cross-talks between mechanical forces and biological functions.
