TY - JOUR
T1 - Nuclear protein transport pathways
AU - Köhler, Matthias
AU - Haller, Hermann
AU - Hartmann, Enno
PY - 1999/7/1
Y1 - 1999/7/1
N2 - Nuclear proteins like transcription factors and ribosomal proteins are synthesized in the cytoplasm and have to be transported into the nucleus to fulfill their functions. The transport of proteins >20-60 kD through the nuclear pore complex (NPC) into the nucleus is an active, energy-requiring process. Transport substrates are recognized by their transport proteins via certain signals. The best-characterized protein import pathway is the 'classical' nuclear localization signal-dependent pathway with importin α and β carrying the substrate to the NPC. The transport of the importin- substrate complex into the nucleus is regulated by the small GTPase Ran/TC4. During the last years more than ten proteins have been discovered which have already been proven or are very likely to be nuclear transport factors of distinct import pathways: member's of the importin α protein family are very similar and transport in complex with importin β nuclear localization signal-bearing proteins into the nucleus. Members of the Ran-binding protein family show some weak similarity to importin β. Sharing a common domain at the amino terminus, they are able to bind RanGTP, a prerequisite for their function as nuclear import or export factors for distinct proteins or RNAs. However, Ran/TC4 seems to play a key regulatory role in all nuclear transport pathways described so far, although the molecular mechanism of the translocation step through the NPC is still unclear.
AB - Nuclear proteins like transcription factors and ribosomal proteins are synthesized in the cytoplasm and have to be transported into the nucleus to fulfill their functions. The transport of proteins >20-60 kD through the nuclear pore complex (NPC) into the nucleus is an active, energy-requiring process. Transport substrates are recognized by their transport proteins via certain signals. The best-characterized protein import pathway is the 'classical' nuclear localization signal-dependent pathway with importin α and β carrying the substrate to the NPC. The transport of the importin- substrate complex into the nucleus is regulated by the small GTPase Ran/TC4. During the last years more than ten proteins have been discovered which have already been proven or are very likely to be nuclear transport factors of distinct import pathways: member's of the importin α protein family are very similar and transport in complex with importin β nuclear localization signal-bearing proteins into the nucleus. Members of the Ran-binding protein family show some weak similarity to importin β. Sharing a common domain at the amino terminus, they are able to bind RanGTP, a prerequisite for their function as nuclear import or export factors for distinct proteins or RNAs. However, Ran/TC4 seems to play a key regulatory role in all nuclear transport pathways described so far, although the molecular mechanism of the translocation step through the NPC is still unclear.
UR - https://www.scopus.com/pages/publications/0345517151
M3 - Journal articles
C2 - 10450016
AN - SCOPUS:0345517151
SN - 1018-7782
VL - 7
JO - Experimental Nephrology
JF - Experimental Nephrology
IS - 4
ER -
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