Table of Contents
What role does clathrin play in endocytosis?
Clathrin-dependent endocytosis allows cells to internalize receptors, ion channels, and extracellular molecules, bringing them into the cell within a protein-coated vesicle. This process involves the formation of special membrane patches called pits, which are defined by the presence of the cytosolic protein clathrin.
What does the clathrin coat do?
Clathrin is involved in coating membranes that are endocytosed from the plasma membrane and those that move between the trans-Golgi network (TGN) and endosomes [11]. When coating membranes, clathrin does not link to the membrane directly, but does so via adaptor proteins.
What does clathrin do in exocytosis?
Clathrin performs critical roles in shaping rounded vesicles in the cytoplasm for intracellular trafficking. Clathrin-coated vesicles (CCV) selectively sort cargo at the cell membrane, trans-Golgi network, and endosomal compartments for multiple membrane traffic pathways.
What do clathrin-coated vesicles do?
Clathrin-coated vesicles mediate trafficking of proteins and nutrients in the cell and between organelles. Proteins included in the clathrin-coated vesicles (CCVs) category include clathrin heavy chain (CHC), clathrin light chain (CLC), and a variety of adaptor protein complexes.
Which process results in the formation of clathrin coated vesicle?
Clathrin-coated vesicles are initiated by the accumulation of adaptor and accessory proteins that bind receptors on the plasma membrane to subsequently drive the nucleation of clathrin [41]. One role of these adaptors is to induce membrane curvature, thereby leading to membrane invagination and vesicle formation.
What is caveolae mediated endocytosis?
Caveolae-mediated endocytosis involves nanoparticles being trafficked to caveolae invaginations on the cell membrane which internalise the particle. Caveolae-mediated endocytosis appears to be a slower process than clathrin-mediated endocytosis although both processes result in similar size endosomes.
What is Caveolae in smooth muscle?
Caveolae are 50- to 90-nm flask-shaped invaginations that appear in rows in periodic register along the longitudinal axis of the smooth muscle membrane, interspersed by regions of dense bodies anchoring the cytoskeleton, as illustrated in Fig. 1A.
What do clathrin coated vesicles do?
Why are caveolae important?
Caveolae regulate fatty acid transport, lipid metabolism and, in the case of adipocytes, lipid storage. Consistent with this, caveolin or cavin dysfunction can lead to lipoatrophy in which adipocyte lipid stores are depleted.
Are AP-2 complexes necessary for the formation of endocytic Clathrin coats?
In summary, our data show that AP-2 complexes are necessary for the formation of endocytic clathrin coats. Our results also eliminate any need to invoke a bypass of AP-2 by alternative adaptors that might function through the endocytic clathrin coated pit/coated vesicle route to explain LDL entry in cells depleted of AP-2.
Which subunits of the Arabidopsis AP-2 interact with clathrin?
Here, we identified all the subunits of the Arabidopsis AP-2 by tandem affinity purification and found that one of the large AP-2 subunits, AP2A1, localized at the PM and interacted with clathrin. Furthermore, endocytosis of the leucine-rich repeat receptor kinase, brassinosteroid insensitive1 (BRI1), was shown to depend on AP-2.
What regulates clathrin-mediated endocytosis in plants?
Clathrin-mediated endocytosis (CME) regulates many aspects of plant development, including hormone signaling and responses to environmental stresses. Despite the importance of this process, the machinery that regulates CME in plants is largely unknown.
What does the AP2M1 variant do?
AP2M1 encodes the μ-subunit of the adaptor protein complex 2 (AP-2), which is involved in clathrin-mediated endocytosis (CME) and synaptic vesicle recycling. Modeling of protein dynamics indicated that the p.Arg170Trp variant impairs the conformational activation and thermodynamic entropy of the AP-2 complex.