| 1. |
- Bai, Ming, et al.
(author)
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ARFGAP1 promotes AP-2-dependent endocytosis
- 2011
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In: Nature Cell Biology. - : Springer Science and Business Media LLC. - 1465-7392 .- 1476-4679. ; 13:5, s. 559-U144
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Journal article (peer-reviewed)abstract
- COPI (coat protein I) and the clathrin-AP-2 (adaptor protein 2) complex are well-characterized coat proteins, but a component that is common to these two coats has not been identified. The GTPase-activating protein (GAP) for ADP-ribosylation factor 1 (ARF1), ARFGAP1, is a known component of the COPI complex. Here, we show that distinct regions of ARFGAP1 interact with AP-2 and coatomer (components of the COPI complex). Selectively disrupting the interaction of ARFGAP1 with either of these two coat proteins leads to selective inhibition in the corresponding transport pathway. The role of ARFGAP1 in AP-2-regulated endocytosis has mechanistic parallels with its roles in COPI transport, as both its GAP activity and coat function contribute to promoting AP-2 transport.
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| 2. |
- Wittrup, Anders, et al.
(author)
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Visualizing lipid-formulated siRNA release from endosomes and target gene knockdown.
- 2015
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In: Nature Biotechnology. - : Springer Science and Business Media LLC. - 1546-1696 .- 1087-0156. ; 33:8, s. 870-870
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Journal article (peer-reviewed)abstract
- A central hurdle in developing small interfering RNAs (siRNAs) as therapeutics is the inefficiency of their delivery across the plasma and endosomal membranes to the cytosol, where they interact with the RNA interference machinery. With the aim of improving endosomal release, a poorly understood and inefficient process, we studied the uptake and cytosolic release of siRNAs, formulated in lipoplexes or lipid nanoparticles, by live-cell imaging and correlated it with knockdown of a target GFP reporter. siRNA release occurred invariably from maturing endosomes within ∼5-15 min of endocytosis. Cytosolic galectins immediately recognized the damaged endosome and targeted it for autophagy. However, inhibiting autophagy did not enhance cytosolic siRNA release. Gene knockdown occurred within a few hours of release and required <2,000 copies of cytosolic siRNAs. The ability to detect cytosolic release of siRNAs and understand how it is regulated will facilitate the development of rational strategies for improving the cytosolic delivery of candidate drugs.
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