Stress fibres-a Ca2+ -independent store for annexins?
Annexins belong to a family of lipid-binding proteins that are implicated in membrane organization. Several members are capable of binding to actin and, in smooth muscle cells, annexin 6 is known to form a Ca(2+)-dependent, plasmalemmal complex with actin filaments. Annexins can also associate with F-actin containing stress fibres within cultured smooth muscle cells or fibroblasts in a Ca(2+)-independent manner. Depolymerization of stress-fibre systems with cytochalasin D leads to the translocation of actin-bound annexin 2 from the cytoplasm to the plasma membrane at high intracellular levels of Ca(2+). This type of Ca(2+)-dependent annexin mobility is observed only in cells of mesenchymal phenotype, which have a well-developed stress-fibre system; not in epithelial cells.
Babiychuk
E B
EB
Department of Cell Biology, Institute of Anatomy, University of Bern, Bühlstrasse 26, 3012, Bern, Switzerland.
Babiychuk
V S
VS
Danilova
V M
VM
Tregubov
V S
VS
Sagach
V F
VF
Draeger
A
A
D017306:Annexin A2 / Q000378:metabolism; D017302:Annexins / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D002118:Calcium / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D002467:Cell Nucleus / Q000737:chemistry; D002478:Cells, Cultured; D015638:Cytochalasin D / Q000494:pharmacology; D004727:Endothelium / Q000737:chemistry / Q000648:ultrastructure; D004847:Epithelial Cells / Q000737:chemistry / Q000648:ultrastructure; D006367:HeLa Cells; D006801:Humans; D007150:Immunohistochemistry; D008648:Mesoderm / Q000166:cytology; D018613:Microscopy, Confocal; D009130:Muscle, Smooth / Q000737:chemistry / Q000648:ultrastructure; D021381:Protein Transport; D022502:Stress Fibers / Q000737:chemistry* / Q000187:drug effects
D017306:Annexin A2; D017302:Annexins; D015638:Cytochalasin D; D002118:Calcium