The GTPase dynamin, a key player in endocytic membrane fission, interacts with numerous proteins that regulate actin dynamics and generate/sense membrane curvature. To determine the functional relationship between these proteins and dynamin, we have analyzed endocytic intermediates that accumulate in cells that lack dynamin (derived from dynamin 1 and 2 double conditional knockout mice). In these cells, actin-nucleating proteins, actin, and BAR domain proteins accumulate at the base of arrested endocytic clathrin-coated pits, where they support the growth of dynamic long tubular necks. These results, which we show reflect the sequence of events in wild-type cells, demonstrate a concerted action of these proteins prior to, and independent of, dynamin and emphasize similarities between clathrin-mediated endocytosis in yeast and higher eukaryotes. Our data also demonstrate that the relationship between dynamin and actin is intimately connected to dynamin's endocytic role and that dynamin terminates a powerful actin- and BAR protein-dependent tubulating activity.
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http://dx.doi.org/10.1016/j.devcel.2009.11.005 | DOI Listing |
Curr Biol
January 2025
Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, 415 South Street, Waltham, MA 02454, USA. Electronic address:
In vivo functions of the septin and actin cytoskeletons are closely intertwined, yet the mechanisms underlying septin-actin crosstalk have remained poorly understood. Here, we show that the yeast-bud-neck-associated Fes/CIP4 homology Bar-amphiphysin-Rvs (F-BAR) protein suppressor of yeast profilin 1 (Syp1)/FCHo uses its intrinsically disordered region (IDR) to directly bind and bundle filamentous actin (F-actin) and to physically link septins and F-actin. Interestingly, the only other F-BAR protein found at the neck during bud development, Hof1, has related activities and also potently inhibits the bud-neck-associated formin Bnr1.
View Article and Find Full Text PDFCell Mol Life Sci
December 2024
Rudbeck Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, 75185, Sweden.
MTSS1 is a ubiquitously expressed intracellular protein known mainly for its involvement in basic cellular processes, such as the regulation of actin organization and membrane architecture. MTSS1 has attracted much attention for its role as a tumor suppressor, being absent or expressed at reduced levels in advanced and metastasizing cancers. Occasionally, MTSS1 is, instead, upregulated in metastasis and, in some cases, even in primary tumors.
View Article and Find Full Text PDFGene
February 2025
The Musculoskeletal Genetics Laboratory, The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, 1311502, Israel; Hebrew SeniorLife, Hinda and Arthur Marcus Institute for Aging Research, Boston, MA 02131, USA. Electronic address:
Understanding the early stages of human congenital myopathies is critical for proposing strategies for improving musculoskeletal muscle performance, such as restoring the functional integrity of the cytoskeleton. SH3 and cysteine-rich domain 3 (STAC3) are proteins involved in nutrient regulation and are an essential component of the excitation-contraction (EC) coupling machinery for Ca releasing. A mutation in STAC3 causes debilitating Native American Myopathy (NAM) in humans, while loss of this gene in mice and zebrafish (ZF) results in premature death.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
October 2024
Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111.
The hair bundle, or stereocilia bundle, is the mechanosensory compartment of hair cells (HCs) in the inner ear. To date, most mechanistic studies have focused on stereocilia bundle morphogenesis, and it remains unclear how this organelle critical for hearing preserves its precise dimensions during life in mammals. The GPSM2-GNAI complex occupies the distal tip of stereocilia in the tallest row and is required for their elongation during development.
View Article and Find Full Text PDFHeliyon
July 2024
Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Indore bypass Road, Bhopal 462 066, Madhya Pradesh, India.
Intracellular membrane tubules play a crucial role in diverse cellular processes, and their regulation is facilitated by Bin-Amphiphysin-Rvs (BAR) domain-containing proteins. This study investigates the roles of ICA69 (dICA69) (an N-BAR protein) and CIP4 (dCIP4) (an F-BAR protein), focusing on their impact on membrane tubule organization. In contrast to the prevailing models of BAR-domain protein function, we observed colocalization of endogenous dICA69 with dCIP4-induced tubules, indicating their potential recruitment for tubule formation and maintenance.
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