Analysis of biophysical and functional consequences of Tropomyosin - fluorescent protein fusions.

The dynamic nature of actin polymers is modulated to facilitate a diverse

range of cellular processes. These dynamic properties are modulated by

different isoforms of Tropomyosin, which are recruited to distinct subpopulations

of actin polymers to differentially modulate their functional

properties. This makes them an attractive target for labelling discrete actin

populations. We have assessed the effect of different fluorescent labelling

strategies for this protein. Although tropomyosin fluorescent fusions

decorate actin in vivo, they are either non-functional or perturb regulation

of actin nucleation and cell cycle timings. Thus conclusions and

physiological relevance should be carefully evaluated when using

tropomyosin fusions.