The role of microRNAs in congenital heart disease

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Quantum chaos in one dimension?

In this work we investigate the inverse of the celebrated Bohigas-Giannoni-Schmit conjecture. Using two inversion methods we compute a one-dimensional potential whose lowest N eigenvalues obey random matrix statistics. Our numerical results indicate that in the asymptotic limit, N->infinity, the solution is nowhere differentiable and most probably nowhere continuous. Thus such a counterexample does not exist.Comment: 7 pages, 10 figures, minor correction, references extende

Formins Determine the Functional Properties of Actin Filaments in Yeast

The actin cytoskeleton executes a broad range of essential functions within a living cell. The dynamic nature of the actin polymer is modulated to facilitate specific cellular processes at discrete locations by actin-binding proteins (ABPs), including the formins and tropomyosins (Tms). Formins nucleate actin polymers, while Tms are conserved dimeric proteins that form polymers along the length of actin filaments. Cells possess different Tm isoforms, each capable of differentially regulating the dynamic and func- tional properties of the actin polymer. However, the mecha- nism by which a particular Tm localizes to a specific actin polymer is unknown. Here we show that specific formin family members dictate which Tm isoform will associate with a particular actin filament to modulate its dynamic and functional properties at specific cellular locations. Exchanging the localization of the fission yeast formins For3 and Cdc12 results in an exchange in localizations of Tm forms on actin polymers. This nucleator-driven switch in filament composition is reflected in a switch in actin dynamics, together with a corresponding change in the filament’s ability to regulate ABPs and myosin motor activity. These data establish a role for formins in dictating which specific Tm variant will associate with a growing actin filament and therefore specify the functional capacity of the actin filaments that they create

Tropomiozin és nehéz meromiozin hatása a formin által nukleált aktin filamentumok flexibilitására

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