Migrasome biogenesis and functions

Abstract

The migrasome is a newly discovered organelle produced by migrating cells. As cells migrate, long and thin retraction fibers are left in their wake. On these fibers, we discovered the production of a pomegranate-like structure, which we named migrasomes. The production of migrasomes is highly correlated with the migration of cells. Currently, it has been demonstrated the migrasomes exhibit three modes of action: release of signaling molecules through rupturing or leaking, carriers of damaged mitochondria, and lateral transfer of mRNA or proteins. In this review, we would like to discuss, in detail, the functions, mechanisms, and potential applications of this newly discovered cell organelle.

Keywords: cell migration; confocal microscopy; migrasomes; tetraspanin; transmission electron microscopy.

Fig. 1

(A) Migrasomes from L929 cells. L929 cells were transfected with Tspan4‐mCherry and visualized by confocal microscopy. Scale bar, 10 mm. (B) Transmission electron microscope image of the pomegranate‐like structures, which we later named migrasomes. Scale bar, 500 nm.

Fig. 2

Assembly of tetraspanin‐enriched macrodomains drives migrasome formation. (A) Tetraspanin‐enriched microdomains (dark red ovals, right panels) are evenly distributed along the retraction fiber prior to migrasome biogenesis. (B) When migrasome biogenesis starts, tetraspanin‐enriched microdomains start to assemble on the migrasome formation site. Such assembly leads to formation of a bulge on the retraction fiber. (C) Eventually, the bulge becomes a spherical vesicle when enough tetraspanin‐enriched microdomains are assembled.

Fig. 3

Three modes of migrasome function. (A) Migrasomes dispose of damaged mitochondria; (B) migrasomes act as packets of information with a delivery address; (C) migrasomes mediate lateral transfer of cellular contents. (D) Unknown functions of migrasome still await discovery.