Cappin' or formin': Formin and capping protein competition for filament ends shapes actin networks.

How cells assemble distinct actin networks from shared cytoplasmic components remains an important unresolved question. In this issue, Wirshing et al. (2023.

Synergy between Wsp1 and Dip1 may initiate assembly of endocytic actin networks.

The actin filament nucleator Arp2/3 complex is activated at cortical sites in to assemble branched actin networks that drive endocytosis. Arp2/3 complex activators Wsp1 and Dip1 are required for proper actin assembly at endocytic sites, but how they coordinately control Arp2/3-mediated actin assembly is unknown. Alone, Dip1 activates Arp2/3 complex without preexisting actin filaments to nucleate 'seed' filaments that activate Wsp1-bound Arp2/3 complex, thereby initiating branched actin network assembly.

Human myosin 1e tail but not motor domain replaces fission yeast Myo1 domains to support myosin-I function during endocytosis.

In both unicellular and multicellular organisms, long-tailed class I myosins function in clathrin-mediated endocytosis. Myosin 1e (Myo1e) in vertebrates and Myo1 in fission yeast have similar domain organization, yet whether these proteins or their individual protein domains are functionally interchangeable remains unknown. In an effort to assess functional conservation of class I myosins, we tested whether human Myo1e could replace Myo1 in fission yeast Schizosaccharomyces pombe and found that it was unable to substitute for yeast Myo1.

The adaptor protein Bbc1 regulates localization of Wsp1 and Vrp1 during endocytic actin patch assembly.

Arp2/3 complex-nucleated branched actin networks provide the key force necessary for endocytosis. The Arp2/3 complex is activated by nucleation-promoting factors including the Wiskott-Aldrich syndrome protein (Wsp1) and myosin-1 (Myo1). There are >40 known yeast endocytic proteins with distinct spatial and temporal localizations and functions; however, it is still unclear how these proteins work together to drive endocytosis.

Catalytic activity, structure and stability of proteinase K in the presence of biosynthesized CuO nanoparticles.

Here, CuO nanoparticles were synthesized using Sambucus nigra (elderberry) fruit extract. Further, the binding of proteinase K, as a model enzyme with green synthesized nanoparticles was investigated. The results demonstrated that the structural changes in enzyme were induced by the binding of nanoparticles.