Annexin A5 is not essential for skeletal development.
Annexins are highly conserved proteins that are characterized by their ability to interact with phospholipids in a calcium-dependent manner. Although diverse functions have been ascribed to annexins based on in vitro analyses, their in vivo functions still remain unclear. The intensively studied annexin A5 has been identified by its effects on blood coagulation, and subsequently, its function as a calcium-specific ion channel was described. In vitro experiments and expression studies suggested a potential role of annexin A5 during calcification processes in vivo, especially in endochondral ossification. To gain insights into the relevance of annexin A5 in this process, we generated an annexin A5-deficient mouse mutant. Mice lacking annexin A5 are viable, are fertile, and reveal no significant alterations in the biochemical parameters characteristic for metabolic or functional defects. Neither the development of skeletal elements nor the in vitro calcification properties of isolated chondrocytes is significantly impaired by the absence of annexin A5. Therefore, annexin A5 is dispensable for the formation and maintenance of skeletal elements in the mouse and may possibly be pointing to a compensatory effect of other members from the annexin family due to their high functional and structural similarity.
Brachvogel
Bent
B
Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Zentrum, Experimentelle Medizin I, Erlangen, Germany.
Dikschas
Jörg
J
Moch
Helga
H
Welzel
Heike
H
von der Mark
Klaus
K
Hofmann
Clementine
C
Pöschl
Ernst
E
D000818:Animals; D000831:Animals, Newborn; D017304:Annexin A5; D017302:Annexins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D001846:Bone Development / Q000235:genetics / Q000502:physiology*; D002113:Calcification, Physiologic / Q000235:genetics; D019902:Chondrocytes / Q000378:metabolism; D018390:Gene Targeting; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010641:Phenotype
D017304:Annexin A5; D017302:Annexins