Endocytic Accessory Proteins Are Functionally Distinguished by Their Differential Effects on the Maturation of Clathrin-coated Pits
Overview
Molecular Biology
Authors
Affiliations
Diverse cargo molecules (i.e., receptors and ligand/receptor complexes) are taken into the cell by clathrin-mediated endocytosis (CME) utilizing a core machinery consisting of cargo-specific adaptors, clathrin and the GTPase dynamin. Numerous endocytic accessory proteins are also required, but their differential roles and functional hierarchy during CME are not yet understood. Here, we used a combination of quantitative live-cell imaging by total internal reflection fluorescence microscopy (TIR-FM), and decomposition of the lifetime distributions of clathrin-coated pits (CCPs) to measure independent aspects of CCP dynamics, including the turnover of abortive and productive CCP species and their relative contributions. Capitalizing on the sensitivity of this assay, we have examined the effects of specific siRNA-mediated depletion of endocytic accessory proteins on CME progression. Of the 12 endocytic accessory proteins examined, we observed seven qualitatively different phenotypes upon protein depletion. From this data we derive a temporal hierarchy of protein function during early steps of CME. Our results support the idea that a subset of accessory proteins, which mediate coat assembly, membrane curvature, and cargo selection, can provide input into an endocytic restriction point/checkpoint mechanism that monitors CCP maturation.
Uptake of oomycete RXLR effectors into host cells by clathrin-mediated endocytosis.
Wang H, Wang S, Wang W, Xu L, Welsh L, Gierlinski M Plant Cell. 2023; 35(7):2504-2526.
PMID: 36911990 PMC: 10291037. DOI: 10.1093/plcell/koad069.
Clathrin coats partially preassemble and subsequently bend during endocytosis.
Mund M, Tschanz A, Wu Y, Frey F, Mehl J, Kaksonen M J Cell Biol. 2023; 222(3).
PMID: 36734980 PMC: 9929656. DOI: 10.1083/jcb.202206038.
Insight into the role of clathrin-mediated endocytosis inhibitors in SARS-CoV-2 infection.
Sami Alkafaas S, Abdallah A, Ghosh S, Loutfy S, Samy ElKafas S, Abdel Fattah N Rev Med Virol. 2022; 33(1):e2403.
PMID: 36345157 PMC: 9877911. DOI: 10.1002/rmv.2403.
Imaging vesicle formation dynamics supports the flexible model of clathrin-mediated endocytosis.
Nawara T, Williams 2nd Y, Rao T, Hu Y, Sztul E, Salaita K Nat Commun. 2022; 13(1):1732.
PMID: 35365614 PMC: 8976038. DOI: 10.1038/s41467-022-29317-1.
Fyn and TOM1L1 are recruited to clathrin-coated pits and regulate Akt signaling.
Cabral-Dias R, Lucarelli S, Zak K, Rahmani S, Judge G, Abousawan J J Cell Biol. 2022; 221(4).
PMID: 35238864 PMC: 8899389. DOI: 10.1083/jcb.201808181.