Possible mechanism of nuclear translocation of proteasomes

FEBS Letters

Fujiwara, Tsutomu²  Tanaka, Keiji¹  Yoshimura, Tetsuro¹  Tamura, Tomohiro¹  Kumatori, Atsushi¹  Ichihara, Akira¹ 

[1] Institute for Enzyme Research, The University of Tokushima, Tokushima 770, Japan;Otsuka Pharmaceutical Company Ltd., Tokushima 771-01, Japan

关键词: Acidic amino acid cluster;    Nuclear location signal;    Proteasome;    20S particle;    Tyrosine phosphorylation site;   

DOI  :  10.1016/0014-5793(90)80367-R

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Proteasomes (multicatalytic proteinase complexes), which are identical to the ubiquitous eukaryotic 20S particles, are localized in both the cytoplasm and the nucleus, but the mechanism of their co-localization in the two compartments is unknown. On examination of the primary structures of subunits of proteasomes, a consensus sequence for nuclear translocation of proteins, X-X-K-K(R)-X-K(R) (where X is any residue), was found to be present in some subunits and to be highly conserved in the subunits of a wide range of eukaryotes. In addition, proteasomal subunits were found to bear a cluster of acidic amino acid residues and also a potential tyrosine phosphorylation site that was located in the same polypeptide chain as the nuclear location signal. These structural properties suggest that two sets of clusters with positive and negative charges serve to regulate the translocation of proteasomes from the cytoplasm to the nucleus, and that phosphorylation of tyrosine in certain subunits may play an additional role in transfer of proteasomes into the nucleus.

【 授权许可】

Unknown