Annexins in the secretory pathway

Abstract

Among the multiplicity of roles suggested for proteins of the annexin family, those implicating these proteins in regulated exocytosis remain among the most convincing. Studies in this area of annexin biology have focused on annexin II, which because of its unusually low Ca(2+)-requirement for phospholipid-binding has many of the requisite properties of a membrane fusogenic Ca2+ sensor. Other annexins are also good candidates for exocytotic mediators, especially annexins I and VII, which have strong vesicle-aggregating activities. In contrast, annexin VI appears to block vesicle aggregation, perhaps acting as a negative regulator of exocytosis. In this review, we consider the evidence for and against annexins having functions in the secretory pathway.

Cholesterol transport from late endosomes to the Golgi regulates t-SNARE trafficking, assembly, and function

“…The role of AnxA6 in secretion has not been extensively investigated, but in line with the data presented here, the available evidence suggests that AnxA6 inhibits rather than potentiates the secretory process (Creutz, 1992; Donnelly and Moss, 1997; Podszywalow-Bartnicka et al , 2010). We previously identified a significant diminution of vesicular stomatitis virus G protein transport (a well-characterized marker for constitutive transport through the secretory pathway) in CHO-A6 cells (Cubells et al , 2007).…”

Identification of Annexin VI as a Ca2+-sensitive CRHSP-28-binding Protein in Pancreatic Acinar Cells

“…Annexin VI is a member of an extended family of Ca 2ϩ -dependent phospholipid-binding proteins reported to function in diverse cellular processes related to signaling, membrane trafficking, and cytoskeletal dynamics (24,26). Annexin proteins are characterized by the presence of at least four conserved tandem repeats of 70 amino acids that mediate their interaction with negatively charged phospholipids in a Ca 2ϩ -dependent manner.…”

Expression of annexin A2 in GABAergic interneurons in the normal rat brain

“…ANX2 is associated with secretory vesicles and involved in endo-and exocytosis (Emans et al 1993;Harder and Gerke 1993;Chasserot-Golaz et al 1996;Donnelly and Moss 1997;Liu 1999;Gruenberg and Stenmark 2004) in the presence of Ca 2+ , ANX2 is capable of forming a heterotetramer composed of two heavy chains (P36) and two light chains (P11). Formation of ANX2 heterotetramer enables its association with lipid rafts on the plasma membrane, where it is proposed to be involved in regulation of protein and membrane trafficking (Waisman 1995;Oliferenko et al 1999;Babiychuk and Draeger 2000;Zobiack et al 2002;Jacob et al 2004).…”