Nuclear pores: Difference between revisions
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Nuclear pores are large [[Protein complexes|protein complexes]] that join the [[Inner nuclear membrane|inner]] and the [[Outer nuclear membrane|outer nuclear membranes]] to each other <ref>http://www.ks.uiuc.edu/Research/npc/</ref>. These pores allow the movement of [[MRNA|mRNA]] out of the [[Nucleus|nucleus]] for [[Translation|translation]].<br> | Nuclear pores are large [[Protein complexes|protein complexes]] that join the [[Inner nuclear membrane|inner]] and the [[Outer nuclear membrane|outer nuclear membranes]] to each other <ref>http://www.ks.uiuc.edu/Research/npc/</ref>. These pores allow the movement of [[MRNA|mRNA]] out of the [[Nucleus|nucleus]] for [[Translation|translation]].<br> | ||
Large molecules travel through the nuclear pores via [[Active transport|active transport]]. Some proteins such as [[Histones|histones]] are relatively small and can pass through the 9nm pores easily. However larger proteins, [[Ribosome|ribosomal subunits]] and [[MRNA|mRNA]] [[Molecules|molecules]] need another mechanism to pass through the [[Nuclear envelope|nuclear envelope]]. This is done via [[Active transport|active transport]]. [[Nuclear Localization Sequences|Nuclear Localization Sequences]] (NLS) on the cargo protein bind to a receptor [[Protein|protein]] called [[Importin|Importin]] to form an [[Importin-cargo complex|Importin-cargo complex]]. This complex is transported into the nucleus where the NLS releases the cargo protein and binds to a [[GTP|GTP]] binding protein called [[Ran|Ran]]. The resulting complex is transported out into the cytoplasm where the importin is recycled <ref>Becker, Kleinsmith, Hardin (2007), The World of the Cell (Published by Pearson Education Inc.), Chapter 18, The Structural Basis of Cellular Information pg 545-546</ref>. | Large molecules travel through the nuclear pores via [[Active transport|active transport]]. Some proteins such as [[Histones|histones]] are relatively small and can pass through the 9nm pores easily. However larger proteins, [[Ribosome|ribosomal subunits]] and [[MRNA|mRNA]] [[Molecules|molecules]] need another mechanism to pass through the [[Nuclear envelope|nuclear envelope]]. This is done via [[Active transport|active transport]]. [[Nuclear Localization Sequences|Nuclear Localization Sequences]] (NLS) on the cargo protein bind to a receptor [[Protein|protein]] called [[Importin|Importin]] to form an [[Importin-cargo complex|Importin-cargo complex]]. This complex is transported into the nucleus where the NLS releases the cargo protein and binds to a [[GTP|GTP]] binding protein called [[Ran|Ran]]. The resulting complex is transported out into the [[Cytoplasm|cytoplasm]] where the importin is recycled <ref>Becker, Kleinsmith, Hardin (2007), The World of the Cell (Published by Pearson Education Inc.), Chapter 18, The Structural Basis of Cellular Information pg 545-546</ref>. | ||
=== References === | === References === | ||
<references /><br> | <references /><br> | ||
Revision as of 22:34, 9 January 2011
Nuclear pores are large protein complexes that join the inner and the outer nuclear membranes to each other [1]. These pores allow the movement of mRNA out of the nucleus for translation.
Large molecules travel through the nuclear pores via active transport. Some proteins such as histones are relatively small and can pass through the 9nm pores easily. However larger proteins, ribosomal subunits and mRNA molecules need another mechanism to pass through the nuclear envelope. This is done via active transport. Nuclear Localization Sequences (NLS) on the cargo protein bind to a receptor protein called Importin to form an Importin-cargo complex. This complex is transported into the nucleus where the NLS releases the cargo protein and binds to a GTP binding protein called Ran. The resulting complex is transported out into the cytoplasm where the importin is recycled [2].
References
- ↑ http://www.ks.uiuc.edu/Research/npc/
- ↑ Becker, Kleinsmith, Hardin (2007), The World of the Cell (Published by Pearson Education Inc.), Chapter 18, The Structural Basis of Cellular Information pg 545-546