Membrane‐bound annexin V isoforms (CaBP33 and CaBP37) and annexin VI in bovine tissues behave like integral membrane proteins

FEBS Letters

Pula, Grazia¹  Ceccarelli, Paolo¹  Giambanco, Ileana¹  Bianchi, Roberta¹  Donato, Rosario¹ 

[1] Section of Anatomy, Department of Experimental Medicine and Biochemical Sciences, University of Perugia, 06100, Perugia, Italy

关键词: Annexin V (CaBP33 and CaBP37);    Annexin VI;    Membrane;    Binding;    Calcium;    Lung;    Heart;    Brain;   

DOI  :  10.1016/0014-5793(92)80369-R

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The distribution of annexin V isoforms (CaBP33 and CaBP37) and of annexin VI in bovine lung, heart, and brain subfractions was investigated with special reference to the fractions of these proteins which are membrane-bound. In addition to EGTA-extractable pools of the above proteins, membranes from lung, heart, and brain contain EGTA-resistant annexins V and VI which can be solubilized with detergents (Triton X-100 or Triton X-114). A strong base like Na₂CO₃, which is usually effective in extracting peripheral membrane proteins, only partially solubilizes the membrane-bound, EGTA-resistant annexins analyzed here. Also, only 50–60% of the Triton X-114-soluble annexins partition in the aqueous phase, the remaining fractions being recovered in the detergent-rich phase. Altogether, these findings suggest that, by an as yet unknown mechanism, following Ca²⁺-dependent association of annexin V isoforms and annexin VI with membranes, substantial fractions of these proteins remain bound to membranes in a Ca²⁺-independent way and behave like integral membrane proteins. These results further support the possibility that the above annexins might play a role in membrane trafficking and/or in the regulation of the structural organization of membranes.

【 授权许可】

Unknown