Compensatory endocytosis in chromaffin cells

Abstract

Exocytosis occurs via fusion of secretory granules with the cell membrane, whereupon the granule content is at least partially released and the granule membrane is temporarily added to the plasma membrane. Exocytosis is balanced by compensatory endocytosis to achieve net equilibrium of the cell surface area and to recycle and redistribute components of the exocytosis machinery. The underlying molecular mechanisms remain a matter of debate. In this review, we summarize and discuss recent progress in the understanding of compensatory endocytosis, with the focus on chromaffin cells as a useful model for studying mechanisms of regulated secretion.

Distinct Apical and Basolateral Membrane Requirements for Stretch-induced Membrane Traffic at the Apical Surface of Bladder Umbrella Cells

“…Presumably the endocytosis we observed in umbrella cells plays similar functions. Compensatory endocytosis in neuroendocrine cells is typically rapid, is initiated by Ca 2ϩ entry into the cell, and is modulated by phosphorylation and dynamin-1, but not clathrin (Barg and Machado, 2008). Our results indicate that compensatory endocytosis in umbrella cells depend on increased basolateral membrane tension and may be modulated by K ϩ channels (see Discussion).…”

“…We further observed that the early stage response was modulated by endocytosis, which was stimulated by increased basolateral membrane tension, occurred after the first phase of outward bowing and predominated during the second phase of this response. In neurons and neuroendocrine cells exocytic bursts are often followed by a compensatory endocytosis, which modulates the increase in plasma membrane surface area, regulates signaling responses, and recovers protein machinery needed for additional rounds of exocytosis (Barg and Machado, 2008). Presumably the endocytosis we observed in umbrella cells plays similar functions.…”

Expression of plasmid DNA in the salivary gland epithelium: novel approaches to study dynamic cellular processes in live animals

“…We sought to determine whether the uptake of plasmid DNA into the acini could be enhanced. It has been suggested that, during exocytosis, membranes delivered during the release of the secretory granules are retrieved by compensatory endocytosis (3,13,36,42). To test whether this process occurs in rat SMGs, we Fig.…”

At the Intersection of the Pathways for Exocytosis and Autophagy

“…For example, lipids and proteins from the plasma membrane are recovered by the cell for cytosolic recycling via compensatory endocytosis, which also allows for the maintenance of membrane homeostasis at the sites of active exocytosis; directing endocytosed membrane back into the endosomal network or Golgi for degradation or recycling (Sramkova et al, 2009). This type of endocytosis is of particular importance in specialized secretory cells, such as, bladder umbrella cells (Khandelwal et al, 2008;Khandelwal et al, 2010), neurons (Kim & von Gersdorff, 2009;Llobet et al, 2011;Logiudice et al, 2009) and neuroendocrine cells (Engisch & Nowycky, 1998;Barg & Machado, 2008). This allows for the rapid recycling of secretory vesicles back into the reserve pool.…”