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As macropinocytosis (also pinocytosis ) refers to the inclusion of amounts of liquid and substances dissolved therein from the surrounding medium of a cell to its interior. The uptake in the cell plasma takes place in the form of vesicles with a maximum diameter of 150 nm. The vesicle is called a macropinosome .

The word is derived from the Greek 'pinein' = drink and 'kytos' = shell.


Macropinocytosis is next to the phagocytosis , the clathrin-mediated endocytosis and the caveolae mediated endocytosis mechanism of endocytosis. Among other things, it occurs in phagocytes . The liquid is absorbed non-specifically without the involvement of receptors for the content. The vesicles then fuse with endosomes and lysosomes in the endomembrane system . In the course of the formation of macropinosomes, Rab7 is increasingly formed. The IP3 kinase and phospholipase C are involved in the formation , whereas cAMP leads to a reintegration of the vesicle into the cell membrane. During the formation of macropinosomes, the phosphoinositides PI (4,5) P2 and PI (3,4,5) P3 are formed and the Rho-GTPase is inactivated. The transport of macropinosomes takes place along the actin - cytoskeleton .

Cell entry for pathogens

The Ebola virus , the vaccinia virus , adenovirus , some picornaviruses and human herpesvirus 8 use Makropinosom-like vesicles for cell entry. The vero toxin formed by EHEC , as well as salmonella , Legionella pneumophila and some protozoa are absorbed into cells via macropinosomes.

Web links

Individual evidence

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  6. J. Mercer, A. Helenius: Virus entry by macropinocytosis. In: Nature cell biology. Volume 11, Number 5, May 2009, pp. 510-520, doi : 10.1038 / ncb0509-510 , PMID 19404330 .
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  8. M. Valiya Veettil, S. Sadagopan, N. Kerur, S. Chakraborty, B. Chandran: Interaction of c-Cbl with myosin IIA regulates Bleb associated macropinocytosis of Kaposi's sarcoma-associated herpesvirus. In: PLoS pathogens. Volume 6, number 12, 2010, p. E1001238, doi : 10.1371 / journal.ppat.1001238 , PMID 21203488 , PMC 3009604 (free full text).
  9. MC Kerr, JT Wang, NA Castro, NA Hamilton, L. Town, DL Brown, FA Meunier, NF Brown, JL Stow, RD Teasdale: Inhibition of the PtdIns (5) kinase PIKfyve disrupts intracellular replication of Salmonella. In: The EMBO journal. Volume 29, number 8, April 2010, pp. 1331-1347, doi : 10.1038 / emboj.2010.28 , PMID 20300065 , PMC 2868569 (free full text).
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