An increase in cytosolic calcium ion concentration precedes hypoosmotic shock‐induced activation of protein kinases in tobacco suspension culture cells

FEBS Letters

Isobe, Minoru³  Muto, Shoshi¹  Takahashi, Koji² 

[1] Nagoya University Bioscience Center, Nagoya University, Chikusa, Nagoya 464-01, Japan;Graduate School of Agricultural Sciences, Nagoya University, Chikusa, Nagoya 464-01, Japan;School of Agricultural Sciences, Nagoya University, Chikusa, Nagoya 464-01, Japan

关键词: Hypoosmotic shock;    Protein kinase;    Cytosolic Ca2+;    Aequorin;    Nicotiana tabacum;    BAPTA;    1;    2-bis(o-aminophenoxy)ethane-N;    N;    N′;    N′-tetraacetic acid;    [Ca2+]cyt;    cytosolic free calcium ion concentration;    MBP;    myelin basic protein;    TCA;    trichloroacetic acid;   

DOI  :  10.1016/S0014-5793(96)01472-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Hypoosmotic shock induced a transient increase in cytosolic free calcium concentration ([Ca²⁺]_cyt) and subsequent activation of 50-, 75- and 80-kDa protein kinases in tobacco (Nicotiana tabacum L.) suspension culture cells. Depletion of external calcium suppressed both the elevation of [Ca²⁺]_cyt and the activation of protein kinases in response to hypoosmotic shock, indicating that the elevation of [Ca²⁺]_cyt is prerequisite for the activation of protein kinases. Pharmacological analysis indicated that the hypoosmotic shock-activated protein kinases were activated by phosphorylation, suggesting that the activities of these protein kinases are regulated by putative protein kinases. These results suggest that the hypoosmotic signal is transduced to protein kinase cascades which are triggered by [Ca²⁺]_cyt elevation.

【 授权许可】

Unknown