bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.64898/2026.06.12.731920

Arp2/3-mediated turnover of large clathrin lattices is regulated through the tyrosine kinase ACK

Hazelbaker, M.·Michalak, D.·Butler, M.·Beach, J.·Taraska, J.·Bear, J.
View original source ↗Export metadata ↓

Abstract

Clathrin mediated endocytosis (CME) is a vital cellular process that mediates cell signaling by controlling the internalization of extracellular cargo and activated receptors. Arp2/3-branched actin provides force to assist in membrane invagination and scission in CME. Loss of Arp2/3-branched actin in conditional Arpc2 KO fibroblasts results in an increase of large arrested clathrin lattices (LACLs) visualized by live-cell TIRF imaging. Additional structural details of LACLs were revealed using electron microscopy and include an increase in arrested clathrin lattices of various curvatures. Numerous CME proteins have heightened levels of tyrosine phosphorylation at these LACLs in Arpc2 KO cells. We identified the non-receptor tyrosine kinase ACK (Activated Cdc42-Associated Kinase) as a key upstream regulator of LACL turnover. CRISPR KO of ACK abrogates LACL tyrosine phosphorylation and impairs cells capacity to resolve LACLs. Our results support a model where ACK recruitment and activation at LACLs drives branched actin formation to help resolve large accumulations of arrested CME structures.

Explore related subjects

Cell BiologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Hazelbaker, M., Michalak, D., Butler, M., Beach, J., Taraska, J., Bear, J.. 2026-06-15. Arp2/3-mediated turnover of large clathrin lattices is regulated through the tyrosine kinase ACK. https://doi.org/10.64898/2026.06.12.731920

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Senescence targeting re-enables injury-responsive repair in a human RPE aging model

Aging is associated with progressive tissue dysfunction and impaired repair after injury. In the retinal pigment epithelium (RPE), these changes contribute to age-related macular degeneration (AMD), yet the mechanisms limiting repair remain incompletely understood. Here, we establish a longitudinal human embryonic stem cell (hESC)-derived RPE aging model that recapitulates key features of aged human donor RPE and combine it with mosaic cell ablation to assess injury-responsive repair. Although aged RPE cells initiate DNA synthesis after injury, they exhibit impaired mitotic progression, uncoupling S-phase entry from epithelial repopulation. Transcriptomic profiling links this defect to a senescence-associated program marked by inflammatory signaling and suppressed mitotic networks. Pharmacologic reduction of senescent cells with Navitoclax shifts aged RPE toward a younger transcriptional profile but does not induce repopulation by itself. Instead, senolytic treatment primes aged RPE for repair, improving epithelial density and homeostatic function only in response to injury, a strategy we term "senolytic priming." These findings establish a human stem-cell-derived platform for investigating age-associated epithelial repair failure and show that aged human RPE retains latent repair capacity that can be re-enabled by targeting cellular senescence.

Cell Biology↗
bioRxiv2026

Bidirectional modulation of aging-associated cellular phenotypes by mitochondrial genome replacement

Mitochondrial dysfunction is a hallmark of cellular aging, but whether age-associated cellular decline can be functionally reversed remains unclear. Here, we applied mitochondrial genome replacement to replicative senescent fibroblasts and aged T cells derived from mice and humans. In senescent fibroblasts, replacement with mitochondria from young cells extended proliferative lifespan, whereas replacement with aged mitochondria accelerated proliferative decline, indicating bidirectional modulation of aging-associated phenotypes. In aged mouse T cells, mitochondrial genome replacement restored proliferative capacity and significantly enhanced antitumor activity following adoptive transfer into tumor-bearing mice. Similarly, mitochondrial genome replacement in aged human T cells enhanced cytokine production and shifted the transcriptomic programs toward a more youthful state. Collectively, these findings identify mitochondrial genetic integrity as a functional regulator of aging-associated cellular states and support the emerging view that mitochondria actively influence cellular aging trajectories.

Cell Biology↗
bioRxiv2026

The MIRO1-BAX Complex Dictates Life and Death at the Mitochondrial Gate

BAX macropores in the outer mitochondrial membrane (OMM) are canonical mediators of apoptosis, but whether the same pore structure can drive distinct cell death pathways remains unclear. Here, we identify the OMM protein MIRO1 as a context-specific modulator of BAX activity. Mechanistically, MIRO1 binds BAX via MIRO1s N-terminal domain to promote macropore formation and the release of mitochondrial DNA (mtDNA) into the cytoplasm, triggering the STING-pIRF3 signaling axis. In glioma cells, this pathway sustains GPX4 expression via pIRF3-mediated transcriptional activation and confers ferroptosis resistance while bypassing inflammation. By contrast, in Parkinsonian neurons, the MIRO1-BAX complex promotes mitochondrial-stress-induced apoptosis. Using structure-guided drug discovery, we developed first-in-class small molecules that allosterically disrupt the MIRO1-BAX complex by engaging MIRO1s distal GTPase pocket. These compounds sensitize glioma cells to ferroptosis and protect neurons from apoptosis. Our findings reveal a disease-specific mitochondrial switch for life-death decisions and illuminate the molecular logic by which cells exploit and interpret OMM permeabilization.

Cell Biology↗