Sandbox8999: Difference between revisions
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===The Canonical Pathway=== | ===The Canonical Pathway=== | ||
Classical endocytosis involving clathrin-coated pits and clathrin-coated vesicles is referred to as the | Classical endocytosis involving clathrin-coated pits and clathrin-coated vesicles is referred to as the canonical clathrin pathway.<ref name="harrison" /> Canonical clathrin-dependent pathways involve the uptake of transferrin (Tf) by transferrin receptor (TfR) and the uptake of LDL by LDL receptors (LDLR).<ref name="harrison" /> Early studies showed that LDL epidermal growth factor (Tf) bound to their specific receptors could be endocytosed within the same vesicle.<ref name="harrison" /> The receptors for these molecules are composed of tails on their cytoplasmic side that contain sequences, which determine cargo sorting and also signal for clathrin to bind.<ref name="harrison" /> Clathrin then coats these vesicles and endocytosis occurs.<ref name="harrison" /> Other pathways, such as reuptake of neurotransmitters into the synaptic cleft, are seen to have similar mechanisms to canonical clathrin pathways.<ref name="harrison" /> | ||
[[Image:Endocytosis.gif |frame| Formation and dissociation of a canonical, endocytitic clathrin-coated pit.<ref name="harrison" />]] | [[Image:Endocytosis.gif |frame| Formation and dissociation of a canonical, endocytitic clathrin-coated pit.<ref name="harrison" />]] | ||
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===The Noncanonical Pathway=== | ===The Noncanonical Pathway=== | ||
The | The noncanonical clathrin pathway refers to clathrin-actin assemblies, which form phagocytotic vesicles in response to invading bacterium.<ref name="harrison" /> Pathogen invasion into nonphagocytic cells result in the recruitment of clathrin.<ref name="harrison" /> These pathogens invade the cell through a process called the “zippering” mechanism, in which actin filaments are utilized to surround the pathogens with the host-cell membrane.<ref name="harrison" /> Actin recruitment requires the formation of clathrin patches and thus the clathrin-assembly forms.<ref name="harrison" /> Actin is not usually needed in classical endocytosis, but it is required when the size of the cargo in the forming vesicle is too large for the vesicle to close.<ref name="harrison" /> This association between actin and clathrin is unique to this pathway and distinguishes the noncanonical from the canonical pathway.<ref name="harrison" /> | ||
== References == | == References == | ||
<references/> | <references/> | ||
