Evidence for existence of a nuclear pore complex-mediated, cytosol-independent pathway of nuclear translocation of ERK MAP kinase in permeabilized cells.

Authors: Matsubayashi, Y., Fukuda, M. and Nishida, E.

Journal: J Biol Chem

Volume: 276

Issue: 45

Pages: 41755-41760

ISSN: 0021-9258

DOI: 10.1074/jbc.M106012200

Abstract:

The classical mitogen-activated protein kinase (MAPK, also known as ERK) pathway is widely involved in eukaryotic signal transductions. In response to extracellular stimuli, MAPK becomes activated and translocates from the cytoplasm to the nucleus. At least two pathways for the nuclear import of MAPK are shown to exist; passive diffusion of a monomer and Ran-dependent active transport of a dimer, the detailed molecular mechanism of which is unknown. In this study, we have reconstituted nuclear import of MAPK in vitro by using digitonin-permeabilized cells with GFP-fused MAPK protein (GFP-MAPK), which is too large to pass through the nuclear pore by passive diffusion. GFP-MAPK was able to accumulate in the nucleus irrespective of its phosphorylation state. This import of GFP-MAPK occurred even in the absence of any soluble cytosolic factors or ATP but was inhibited by wheat germ agglutinin or an excess amount of importin-beta or at low temperatures. Moreover, MAPK directly bound to an FG repeat region of nucleoporin CAN/Nup214 in vitro. Taken together, these results suggest the third pathway for nuclear import of MAPK, in which MAPK passes through the nuclear pore by directly interacting with the nuclear pore complex.

Source: PubMed

Evidence for existence of a nuclear pore complex-mediated, cytosol-independent pathway of nuclear translocation of ERK MAP kinase in permeabilized cells

Authors: Matsubayashi, Y., Fukuda, M. and Nishida, E.

Journal: JOURNAL OF BIOLOGICAL CHEMISTRY

Volume: 276

Issue: 45

Pages: 41755-41760

eISSN: 1083-351X

ISSN: 0021-9258

DOI: 10.1074/jbc.M106012200

Source: Web of Science (Lite)

Evidence for existence of a nuclear pore complex-mediated, cytosol-independent pathway of nuclear translocation of ERK MAP kinase in permeabilized cells.

Authors: Matsubayashi, Y., Fukuda, M. and Nishida, E.

Journal: The Journal of biological chemistry

Volume: 276

Issue: 45

Pages: 41755-41760

eISSN: 1083-351X

ISSN: 0021-9258

DOI: 10.1074/jbc.m106012200

Abstract:

The classical mitogen-activated protein kinase (MAPK, also known as ERK) pathway is widely involved in eukaryotic signal transductions. In response to extracellular stimuli, MAPK becomes activated and translocates from the cytoplasm to the nucleus. At least two pathways for the nuclear import of MAPK are shown to exist; passive diffusion of a monomer and Ran-dependent active transport of a dimer, the detailed molecular mechanism of which is unknown. In this study, we have reconstituted nuclear import of MAPK in vitro by using digitonin-permeabilized cells with GFP-fused MAPK protein (GFP-MAPK), which is too large to pass through the nuclear pore by passive diffusion. GFP-MAPK was able to accumulate in the nucleus irrespective of its phosphorylation state. This import of GFP-MAPK occurred even in the absence of any soluble cytosolic factors or ATP but was inhibited by wheat germ agglutinin or an excess amount of importin-beta or at low temperatures. Moreover, MAPK directly bound to an FG repeat region of nucleoporin CAN/Nup214 in vitro. Taken together, these results suggest the third pathway for nuclear import of MAPK, in which MAPK passes through the nuclear pore by directly interacting with the nuclear pore complex.

Source: Europe PubMed Central