by Keyword: Biological Sciences

Prischich D, Camarero N, Encinar Del Dedo J, Cambra-Pellejà M, Prat J, Nevola L, Martín-Quirós A, Rebollo E, Pastor L, Giralt E, Geli MI, Gorostiza P, (2023). Light-dependent inhibition of clathrin-mediated endocytosis in yeast unveils conserved functions of the AP2 complex Iscience 26, 107899

Clathrin-mediated endocytosis (CME) is an essential cellular process, conserved among eukaryotes. Yeast constitutes a powerful genetic model to dissect the complex endocytic machinery, yet there is a lack of specific pharmacological agents to interfere with CME in these organisms. TL2 is a light-regulated peptide inhibitor targeting the AP2-β-adaptin/β-arrestin interaction and that can photocontrol CME with high spatiotemporal precision in mammalian cells. Here, we study endocytic protein dynamics by live-cell imaging of the fluorescently tagged coat-associated protein Sla1-GFP, demonstrating that TL2 retains its inhibitory activity in S. cerevisiae spheroplasts. This is despite the β-adaptin/β-arrestin interaction not being conserved in yeast. Our data indicate that the AP2 α-adaptin is the functional target of activated TL2. We identified as interacting partners for the α-appendage, the Eps15 and epsin homologues Ede1 and Ent1. This demonstrates that endocytic cargo loading and sensing can be executed by conserved molecular interfaces, regardless of the proteins involved.© 2023 The Author(s).

JTD Keywords: Biochemistry, Biological sciences, Cell biology, Molecular biology, Natural sciences

Lerche, Martina, Elosegui-Artola, Alberto, Kechagia, Jenny Z., Guzmán, Camilo, Georgiadou, Maria, Andreu, Ion, Gullberg, Donald, Roca-Cusachs, Pere, Peuhu, Emilia, Ivaska, Johanna, (2020). Integrin binding dynamics modulate ligand-specific mechanosensing in mammary gland fibroblasts iScience 23, (3), 100907

The link between integrin activity regulation and cellular mechanosensing of tissue rigidity, especially on different extracellular matrix ligands, remains poorly understood. Here, we find that primary mouse mammary gland stromal fibroblasts (MSFs) are able to spread efficiently, generate high forces, and display nuclear YAP on soft collagen-coated substrates, resembling the soft mammary gland tissue. We describe that loss of the integrin inhibitor, SHARPIN, impedes MSF spreading specifically on soft type I collagen but not on fibronectin. Through quantitative experiments and computational modeling, we find that SHARPIN-deficient MSFs display faster force-induced unbinding of adhesions from collagen-coated beads. Faster unbinding, in turn, impairs force transmission in these cells, particularly, at the stiffness optimum observed for wild-type cells. Mechanistically, we link the impaired mechanotransduction of SHARPIN-deficient cells on collagen to reduced levels of collagen-binding integrin α11β1. Thus integrin activity regulation and α11β1 play a role in collagen-specific mechanosensing in MSFs.

JTD Keywords: Biological Sciences, Cell Biology, Functional Aspects of Cell Biology