In biology, an endosome is a membrane-bound compartment inside cells. Many endocytotic vesicles derived from the plasma membrane are transported to an endosome and fuse with it. Some endocytosed material passes through endosomes on its way to lysosomes. Endosomes are in part responsible for the sorting of endocytosed material before transport to lysosomes. This allows some material to be returned to the plasma membrane.
Annexin VI
- a marker protein of hepatocytic endosomes. PMID: 7904597
EEA1
- a peripheral membrane protein associated with the cytoplasmic face of early endosomes, controls vesicle fusion during endocytosis, as extensively studied in non-neuronal cells. PMID: 17113235
ESCRT
- found on tubular-vesicular endosomal membranes rather than on endosomes themselves. The ESCRT labeling was twice as concentrated on early and late endosomes/lysosomes in macrophages compared with that in T cells, where it was twice more abundant at the plasma membrane. PMID: 17014699
Rab5
- a regulatory guanosine triphosphatase that is associated with the sorting endosome and participates in endosomal membrane fusion reactions. PMID: 11208157
- localized on early endosomes and on the cytoplasmic face of the plasma membrane, is involved in the process of early endosome fusion. PMID: 1900457
Rab7 and Lamp1
- late endosomal and lysosomal membrane markers. PMID: 7868367
Rap1
- Both GFP-tagged Rap1 and endogenous Rap1 were localized to the plasma membrane (PM) and endosomes. PMID: 14757755
Syntaxin 7
- localized to late endosome compartments, associates with Vamp 8, and Is required for late endosome-lysosome fusion. PMID: 10982406
- Syntaxin7 as a soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) required for late endosome-lysosome and homotypic lysosome fusion in vitro. PMID: 10888671
Syntaxin 8
- a novel member of the syntaxin family, is localized to the early endosome marked by Rab5. PMID: 10683148
Syntaxin 12
- a member of the syntaxin family localized to the endosome. PMID: 9507000
VAMP-7 (vesicle-associated membrane protein-7)
- a SNARE required for late endosome-lysosome fusion. PMID: 10888671
Other Endosome Makers
- semiconductor quantum dots (QDs)/sheep serum albumin (SSA) complex, therefore, can be used as a long-life and highly photostable endosome marker. PMID: 12615061