Isolation, characterization and localization of annexin V from chicken liver

Abstract

Annexin V has been purified from chicken liver; 40 mg of annexin V was obtained per kg of tissue. In contrast with mammalian liver, very little annexin VI was obtained. Surprisingly, chicken liver annexin V resembles mammalian annexin IV in its M(r) (32,500) and its isoelectric point (5.6), but amino-acid-sequence analysis demonstrates identity with chicken annexin V (anchorin CII). It binds to phospholipids in a Ca(2+)-dependent manner with free-Ca2+ concentrations for half-maximal binding to phosphatidylserine and phosphatidic acid of 10 microM; phosphatidylethanolamine of 32 microM and phosphatidylinositol of 90 microM. No binding to phosphatidylcholine was observed at Ca2+ concentrations up to 300 microM. In isolated liver membranes a significant proportion of annexin V was not extractable with EGTA but could only be extracted with Triton X-100, suggesting the existence of a tightly membrane-associated form of annexin V. A specific antiserum to chicken annexin V was used to localize the protein in adult and embryonic chicken liver. In the adult, annexin V was highly concentrated in epithelial cells lining the bile ducts, and along the bile canaliculi. In embryonic liver, strong staining of the bile-duct epithelial cells was again evident, and in addition, endothelial cells were strongly immunoreactive.

Relocation of annexin V to platelet membranes is a phosphorylation-dependent process

“…In addition, subcellular fractionation studies have shown that in heart, lung, liver, platelets and brain a proportion of the total annexin V remains associated with membranes even after extraction with EGTA. It is therefore likely that annexin V plays a role in the regulation of a membranelocalized process [7,8,[25][26][27][28]. We have demonstrated that, following physiological platelet activation, annexin V relocates from the cytosol and binds to membranes, which implicates annexin V in coupling increases in cytosolic [Ca# + ] to membranespecific processes [7,8].…”

Characterization of platelet aminophospholipid externalization reveals fatty acids as molecular determinants that regulate coagulation

“…This protein recognizes APL on the platelet surface and is used as a nonquantitative probe (6)(7)(8). In recent years it has been described as detecting PS exposure, although several annexins also bind PE (6,(9)(10)(11)(12)(13). Other proteins that indirectly measure APL exposure include lactadherin and cinnamycin, reported as specific PS or PE indicators, respectively (14)(15)(16).…”

Two Novel Intrinsic Annexins Accumulate in Wheat Membranes in Response to Low Temperature

“…They are usually considered as soluble calcium dependent phospholipid binding proteins but recent reports have suggested that they could also be tightly associated with cellular membranes (Sheets et al 1987, Valentine-Braun et al 1987, Campos-Gonzales et al 1989, Pula et al 1990, Bianchi et al 1992, Boustead et al 1993, Futter et al 1993, Tagoe et al 1994, Bohm et al 1994, Trotter et al 1994, Blanchard et al 1996, Liu et al 1997, Harder et al 1997, Jost et al 1997, Turpin et al 1998. Annexins have a common structure consisting of a core domain of four or eight repeated sequences containing calcium and phospholipid binding sites.…”