Evidence for the presence of high‐M r microtubule‐associated proteins and their Ca2+‐dependent proteolysis in synaptosomal cytosol

FEBS Letters

Burgoyne, Robert D.¹  Cumming, Richard¹ 

[1] Laboratory of Biological Ultrastructure, National Institute for Medical Research, Mill Hill, London NW7 1AA, England

关键词: Calcium;    Microtubule;    Microtubule-associated protein;    Nerve terminal;    Synaptosome;    Protease;   

DOI  :  10.1016/0014-5793(82)80933-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Calcium-dependent proteolysis of several polypeptides from rat brain and synaptosomal cytosol was observed including proteolysis of polypeptides of M _r 340 000 and 300 000. These latter polypeptides comigrated with high-M _r microtubule-associated proteins of microtubule preparations from brain or synaptosomal cytosol. Calcium influx into intact synaptosomes due to depolarisation with high potassium or veratridine or treatment with the ionophore A23187 did not result in Ca²⁺-dependent proteolysis of any polypeptides. This may be due to the low calcium sensitivity of the protease since no proteolysis of the M _r 340 000 and 300 000 polypeptides was seen in synaptosomal cytosal at < 10 μM free Ca²⁺.

【 授权许可】

Unknown