Exosomes biogenesis

Pant, S., Hilton, H., Burczynski, M.E., 2012. The multifaceted exosome biogenesis, role in normal and aberrant cellular function, and frontiers for pharmacological and biomarker... 

Historically, the word exosome, (beside designating the multienzyme ribonuclease complex identified in S, cerevisiae), has been used to define different types of vesicles released by cells (Figure 1). We feel it is critical to differentiate between the various kinds of vesicles since their mode of biogenesis could be directly related to their physiologic function and/or to the state of the productive cell. 

Table 2 is a compilation of 11 proteomic studies of exosomes released by various cells in culture, compared with the data of the complete study done on exosomes collected from urine. Note that of the 22 proteins found in at least 4 of the 11 studies, 20 were also found in urine exosomes. These findings suggest that these proteins are very likely involved in the biogenesis or sorting of molecules in the vesicles. Other proteins are not systematically found in the various studies and might reflect variation between cell types, such as differential expression of cargo proteins. 

At this point in time, the physiologic function of exosomes is far from clear. Various roles have been suggested depending on the cell type producing the vesicles. As their mode of biogenesis likely involves ESCRT machinery, we anticipate that a function... 

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