Importin beta: Conducting a much larger cellular symphony

Amnon Harel, Douglass J. Forbes

Research output: Contribution to journalReview articlepeer-review

314 Scopus citations


Importin β, once thought to be exclusively a nuclear transport receptor, is emerging as a global regulator of diverse cellular functions. Importin β acts positively in multiple interphase roles: in nuclear import, as a chaperone for highly charged nuclear proteins, and as a potential motor adaptor for movement along microtubules. In contrast, importin β plays a negative regulatory role in mitotic spindle assembly, centrosome dynamics, nuclear membrane formation, and nuclear pore assembly. In most of these, importin β is counteracted by its regulator, Ran-GTP. In light of this, the recent discovery of Ran's involvement in spindle checkpoint control suggested a potential new arena for importin β action, although it is also possible that one of importin β's relatives, the karyopherin family of proteins, manages this checkpoint. Lastly, importin β plays a role in transducing damage signals from the axons of injured neurons back to the cell body.

Original languageEnglish
Pages (from-to)319-330
Number of pages12
JournalMolecular Cell
Issue number3
StatePublished - 5 Nov 2004
Externally publishedYes

Bibliographical note

Funding Information:
The current papers concerning importin β and the karyopherins number close to a thousand; the authors regret that only a fraction could be cited. The authors were supported by National Institutes of Health grant R01-GM033279 to D.J.F. and a United States-Israel Bi-national Sciences Foundation Grant 200295 to D.F. and Michael Elbaum (Weizmann Institute, Rehovot, Israel). The authors thank Rene Chan, Valerie Delmar, and Corine Lau for help in preparing the manuscript.


Dive into the research topics of 'Importin beta: Conducting a much larger cellular symphony'. Together they form a unique fingerprint.

Cite this