This Article Full Text Full Text (PDF) An erratum has been published Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Leslie, D. M. Articles by Aitchison, J. D. Search for Related Content PubMed PubMed Citation Articles by Leslie, D. M. Articles by Aitchison, J. D.

Characterization of Karyopherin Cargoes Reveals Unique Mechanisms of Kap121p-Mediated Nuclear Import

Institute for Systems Biology, Seattle, Washington,¹ Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada,² The Rockefeller University, New York, New York³

Received 2 February 2004/ Returned for modification 8 March 2004/ Accepted 30 June 2004

In yeast there are at least 14 members of the ß-karyopherin protein family that govern the movement of a diverse set of cargoes between the nucleus and cytoplasm. Knowledge of the cargoes carried by each karyopherin and insight into the mechanisms of transport are fundamental to understanding constitutive and regulated transport and elucidating how they impact normal cellular functions. Here, we have focused on the identification of nuclear import cargoes for the essential yeast ß-karyopherin, Kap121p. Using an overlay blot assay and coimmunopurification studies, we have identified 30 putative Kap121p cargoes. Among these were Nop1p and Sof1p, two essential trans-acting protein factors required at the early stages of ribosome biogenesis. Characterization of the Kap121p-Nop1p and Kap121p-Sof1p interactions demonstrated that, in addition to lysine-rich nuclear localization signals (NLSs), Kap121p recognizes a unique class of signals distinguished by the abundance of arginine and glycine residues and consequently termed rg-NLSs. Kap104p is also known to recognize rg-NLSs, and here we show that it compensates for the loss of Kap121p function. Sof1p is also transported by Kap121p; however, its import can be mediated by a piggyback mechanism with Nop1p bridging the interaction between Sof1p and Kap121p. Together, our data elucidate additional levels of complexity in these nuclear transport pathways.

This article has been cited by other articles:

• Lange, A., Mills, R. E., Devine, S. E., Corbett, A. H. (2008). A PY-NLS Nuclear Targeting Signal Is Required for Nuclear Localization and Function of the Saccharomyces cerevisiae mRNA-binding Protein Hrp1. J. Biol. Chem. 283: 12926-12934 [Abstract] [Full Text]  
• Badugu, R., Garcia, M., Bondada, V., Joshi, A., Geddes, J. W. (2008). N Terminus of Calpain 1 Is a Mitochondrial Targeting Sequence. J. Biol. Chem. 283: 3409-3417 [Abstract] [Full Text]  
• Demoinet, E., Jacquier, A., Lutfalla, G., Fromont-Racine, M. (2007). The Hsp40 chaperone Jjj1 is required for the nucleo-cytoplasmic recycling of preribosomal factors in Saccharomyces cerevisiae. RNA 13: 1570-1581 [Abstract] [Full Text]  
• Selitrennik, M., Duek, L., Lotan, R., Choder, M. (2006). Nucleocytoplasmic Shuttling of the Rpb4p and Rpb7p Subunits of Saccharomyces cerevisiae RNA Polymerase II by Two Pathways. Eukaryot Cell 5: 2092-2103 [Abstract] [Full Text]  
• Timney, B. L., Tetenbaum-Novatt, J., Agate, D. S., Williams, R., Zhang, W., Chait, B. T., Rout, M. P. (2006). Simple kinetic relationships and nonspecific competition govern nuclear import rates in vivo. J. Cell Biol. 175: 579-593 [Abstract] [Full Text]  
• Smaldone, S., Ramirez, F. (2006). Multiple pathways regulate intracellular shuttling of MoKA, a co-activator of transcription factor KLF7. Nucleic Acids Res 0: gkl659v3-9 [Abstract] [Full Text]  
• Lebreton, A., Saveanu, C., Decourty, L., Rain, J.-C., Jacquier, A., Fromont-Racine, M. (2006). A functional network involved in the recycling of nucleocytoplasmic pre-60S factors. J. Cell Biol. 173: 349-360 [Abstract] [Full Text]  
• Bakhrat, A., Baranes, K., Krichevsky, O., Rom, I., Schlenstedt, G., Pietrokovski, S., Raveh, D. (2006). Nuclear Import of Ho Endonuclease Utilizes Two Nuclear Localization Signals and Four Importins of the Ribosomal Import System. J. Biol. Chem. 281: 12218-12226 [Abstract] [Full Text]  
• An, X., Zhang, Z., Yang, K., Huang, M. (2006). Cotransport of the Heterodimeric Small Subunit of the Saccharomyces cerevisiae Ribonucleotide Reductase Between the Nucleus and the Cytoplasm. Genetics 173: 63-73 [Abstract] [Full Text]  
• Bax, R., Vos, H. R., Raue, H. A., Vos, J. C. (2006). Saccharomyces cerevisiae Sof1p Associates with 35S Pre-rRNA Independent from U3 snoRNA and Rrp5p. Eukaryot Cell 5: 427-434 [Abstract] [Full Text]  
• Liku, M. E., Nguyen, V. Q., Rosales, A. W., Irie, K., Li, J. J. (2005). CDK Phosphorylation of a Novel NLS-NES Module Distributed between Two Subunits of the Mcm2-7 Complex Prevents Chromosomal Rereplication. Mol. Biol. Cell 16: 5026-5039 [Abstract] [Full Text]  
• Hodges, J. L., Leslie, J. H., Mosammaparast, N., Guo, Y., Shabanowitz, J., Hunt, D. F., Pemberton, L. F. (2005). Nuclear Import of TFIIB Is Mediated by Kap114p, a Karyopherin with Multiple Cargo-binding Domains. Mol. Biol. Cell 16: 3200-3210 [Abstract] [Full Text]