Signal-mediated nuclear export of proteins and RNAs
- 作者：Bachelerie ; Franç ; oise ; Rodriguez ; M ; Arenzana-Seisdedos ; F ; Ossareh-Nazari ; B ; Dargemont ; C.
- 刊名：Biology of the Cell
- 出版年：1998
- 期刊代码：11_02484900
- 类别：imm
- 出版时间：January, 1998
- 卷：90
- 期：1
- 页码：96-97
- 文件大小：168 K
摘要
The characterization of nuclear export signals (NESs) in a number of rapidly shuttling proteins revealed the occurrence of signal-dependent transport of proteins from the nucleus to the cytoplasm. Although passage of small proteins (<40kDa) through nuclear envelope pores can occur by passive diffusion, the import of larger proteins, as well as RNAs, is temperature- and energy-dependent. NES-mediated nuclear export, like nuclear import, is an active process and is much faster that the slow nuclear egress of proteins lacking an NES element. Analysis of the trafficking pathway of proteins shuttling back and forth between the nucleus and the cytoplasm led to the identification of two types of specific signals for nuclear export. One is present in hnRNP A1 (heteronuclear ribonucleoprotein particles) and functions also as a nuclear import signal. The other one is a hydrophobic-rich short amino-acid sequence (usually leucine) of defined spacing and was originally described in the cAMP-dependent protein kinase A inhibitor (PKI). After appropriate stimulation and diffusion into the nucleus of the catalytic subunit of cAMP-dependent protein kinase (c-PKA), the binding of this subunit to PKI triggers rapid nuclear export of the complex (PKI/c-PKA).