What happens to embedded membrane proteins after a vesicle is formed?
Endosome formation.
For the sake of keeping this somewhat brief, I'm going to stay somewhat surface level.
When a vesicle is endocytosed, it is called a primary endocytic vesicle.
When multiple primary endocytic vesicles fuse together, they form a larger entity called an early endosome.
Early endosomes can also be called &quot;sorting endosomes&quot; because different portions of the vesicle are sorted into different destinations, including these things called &quot;recycling endosomes.&quot;
Transmembrane proteins in endosomes
In my experience, transmembrane proteins largely get sorted into these recycling endosomes and are then re-inserted into the cell membrane.
To my knowledge and from some cursory review on the topic, this is a common outcome for transmembrane proteins; they are eventually recycled and placed back into the cell membrane via exocytosis after being sorted into a recycling endosome.
Further reading
I'm sure others can add more explanation and some of the alternative routes these proteins can take, but in the interest of brevity and clarity, I thought it best to just stick with what I've come to know as most common.
Also, if you'd like a helpful source, see if you can get access to the following paper through a school or library service: Elkin, S. R., Lakoduk, A. M., &amp; Schmid, S. L. (2016). Endocytic pathways and endosomal trafficking: a primer. Wiener Medizinische Wochenschrift, 166(7-8), 196-204.
In a phenomenon that I think is really cool, some receptors are thought to actually keep functioning after they are endocytosed and form these things called &quot;signalling endosomes&quot; (search &quot;signalling endosomes NGF and TrkA&quot; to read more).