C-JUN: Difference between revisions
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== Introduction == | == Introduction == | ||
The c-Jun protein is a member of transcription factors which consist of a basic region leucine zipper region <ref name="one">PMID:8662824</ref>. Originally identified by its homology to v-jun, the oncogene from the avian sarcomoa virus <ref name="four"/> Bossy-Wetzel, E., Bakiri, L., Yaniv, M. (1997). Induction of apoptosis by the transcription factor c-Jun. EMO Journal. Vol.16;7. 1695-1709 </ref>. All these leucine zipper factors bind to DNA in one of two states: homo or heterodimers <ref name="two">PMID:8662824</ref>. In conjunction with the c-Fos protein these two proteins bind to specific regions of DNA strands. Together these two proteins form the c-fos/c-jun complex which help regulate cell growth and differentiation <ref name="one">. The members of the jun and fos families include three Jun proteins and four Fos proteins (c-Jun, JunB, JunD,c-Fos, Fos-B, Fra1, and Fra2) <ref name="one"/>. Regulation of the complex iteslf is done by interactions between the protein and DNA in addition to the protein-protein interactions between each of the leucine zipper domains <ref name="one"/>. | The c-Jun protein is a member of transcription factors which consist of a basic region leucine zipper region <ref name="one"> PMID:8662824 </ref>. Originally identified by its homology to v-jun, the oncogene from the avian sarcomoa virus <ref name="four" /> Bossy-Wetzel, E., Bakiri, L., Yaniv, M. (1997). Induction of apoptosis by the transcription factor c-Jun. EMO Journal. Vol.16;7. 1695-1709 </ref>. All these leucine zipper factors bind to DNA in one of two states: homo or heterodimers <ref name="two"> PMID:8662824 </ref>. In conjunction with the c-Fos protein these two proteins bind to specific regions of DNA strands. Together these two proteins form the c-fos/c-jun complex which help regulate cell growth and differentiation <ref name="one" />. The members of the jun and fos families include three Jun proteins and four Fos proteins (c-Jun, JunB, JunD,c-Fos, Fos-B, Fra1, and Fra2) <ref name="one" />. Regulation of the complex iteslf is done by interactions between the protein and DNA in addition to the protein-protein interactions between each of the leucine zipper domains <ref name="one" />. | ||
== Structure Overview == | == Structure Overview == | ||
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[[Image:1jun.png|left|thumb|''Figure 1.'' A 3-D representation of the two alpha helices which form a coiled coil [http://www.rcsb.org/pdb/explore/jmol.do?structureId=1JUN] ]] | [[Image:1jun.png|left|thumb|''Figure 1.'' A 3-D representation of the two alpha helices which form a coiled coil [http://www.rcsb.org/pdb/explore/jmol.do?structureId=1JUN] ]] | ||
The structure of c-Jun is comprised of a leucine zipper as previously stated. This dimerization motif may be in one of two classes, both of which are required for DNA-binding transcription factors; the basic-domain leucine zipper proteins (bZIP) and the basic helix loop-helix-leucine zipper proteins(bHLH-ZIP) <ref name="two" | The structure of c-Jun is comprised of a leucine zipper as previously stated. This dimerization motif may be in one of two classes, both of which are required for DNA-binding transcription factors; the basic-domain leucine zipper proteins (bZIP) and the basic helix loop-helix-leucine zipper proteins(bHLH-ZIP) <ref name="two"> A Junius, F.K., Mackay, J.P., Bubb, W.A., Jensen, S.A., Weiss, A.S., King, G.F. 2006. Nuclear Magnetic Resonance Characterization of the Jun Leucine Zipper Domain: Unusual Properties of Coiled-Coil Interfacial Polar Residues?</ref>. The strand becomes an elongated coiled coil. This is formed by residues at the a and d positions in each of the two monomers, whereby they create hydrophobic centers which conform to the "knobs into holes" model by Crick. <ref name="two" />. Amino acids at these a and d positions are each surrounded by 4 additional residues from adjacent a-helix monomer <ref name="two" />. | ||
The a and d residues each exhibit varying types of packing in terms of this "knobs into holes" theory. According to Harbury et al.(24) the leucines at the a positions are packed "parallel" in such a way that the C-alpha-C-beta bond vector lies in a parallel manner to the C-alpha-C-alpha vector at the base of the acceptor hole on adjacent helix <ref name="one"/>. Whereas the opposite is true for the leucines in the d positions. Here the residues are packed in a "perpendicular" nature <ref name="one"/>. The bond vector of the C-alpha-C-beta pack approximately perpendicular to the C-alpha-C-alpha vector at the base of the hole of the second helix in which it packs <ref name="one"/>. Therefore only the leucine side chains in the a positions, which point away from the boundary, make van der Waals interactions <ref name="one"/>. | The a and d residues each exhibit varying types of packing in terms of this "knobs into holes" theory. According to Harbury et al.(24) the leucines at the a positions are packed "parallel" in such a way that the C-alpha-C-beta bond vector lies in a parallel manner to the C-alpha-C-alpha vector at the base of the acceptor hole on adjacent helix <ref name="one"/>. Whereas the opposite is true for the leucines in the d positions. Here the residues are packed in a "perpendicular" nature <ref name="one"/>. The bond vector of the C-alpha-C-beta pack approximately perpendicular to the C-alpha-C-alpha vector at the base of the hole of the second helix in which it packs <ref name="one"/>. Therefore only the leucine side chains in the a positions, which point away from the boundary, make van der Waals interactions <ref name="one"/>. | ||