Editing Endocytosis (section)

=== Processes and components ===

Caveolin proteins like caveolin-1 ([[Caveolin 1|CAV1]]), caveolin-2 ([[Caveolin 2|CAV2]]), and caveolin-3 ([[Caveolin 3|CAV3]]), play significant roles in the caveolar formation process. More specifically, CAV1 and CAV2 are responsible for caveolae formation in non-muscle cells while CAV3 functions in muscle cells. The process starts with CAV1 being synthesized in the [[Endoplasmic reticulum|ER]] where it forms detergent-resistant [[oligomer]]s. Then, these oligomers travel through the [[Golgi Complex|Golgi complex]] before arriving at the cell surface to aid in caveolar formation. Caveolae formation is also reversible through disassembly under certain conditions such as increased plasma membrane tension. These certain conditions then depend on the type of tissues that are expressing the caveolar function. For example, not all tissues that have caveolar proteins have a caveolar structure i.e. the [[Blood-brain-barrier|blood-brain barrier]].<ref name="pmid">{{cite journal | vauthors = Parton RG, Tillu VA, Collins BM | title = Caveolae | journal = Current Biology | volume = 28 | issue = 8 | pages = R402–R405 | date = April 2018 | pmid = 29689223| doi = 10.1016/j.cub.2017.11.075 | s2cid = 235331463 | doi-access = free }}</ref>
Though there are many morphological features conserved among caveolae, the functions of each CAV protein are diverse. One common feature among caveolins is their hydrophobic stretches of potential hairpin structures that are made of [[α-helices]]. The insertion of these hairpin-like α-helices forms a caveolae coat which leads to membrane curvature. In addition to insertion, caveolins are also capable of oligomerization which further plays a role in membrane curvature. Recent studies have also discovered that polymerase I, transcript release factor, and serum deprivation protein response also play a role in the assembly of caveolae. Besides caveolae assembly, researchers have also discovered that CAV1 proteins can also influence other endocytic pathways. When CAV1 binds to [[CDC42|Cdc42]], CAV1 inactivates it and regulates Cdc42 activity during membrane trafficking events.<ref name="pmid20125123">{{cite journal | vauthors = Kumari S, Mg S, Mayor S | title = Endocytosis unplugged: multiple ways to enter the cell | journal = Cell Research | volume = 20 | issue = 3 | pages = 256–75 | date = March 2010 | pmid = 20125123 | doi = 10.1038/cr.2010.19 | pmc = 7091825 }}</ref>