Sandbox Reserved 598: Difference between revisions
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[[Image:MyJak2.jpg|thumb|250px|left|Not, "just another kinase". Picture from Protein Data Bank.]] | [[Image:MyJak2.jpg|thumb|250px|left|Not, "just another kinase". Picture from Protein Data Bank.]] | ||
Janus Kinase 2 is a non-receptor janus kinase, a protein which is part of the tyrosine kinases. These group of kinases are the primary intracellular mediators of cytokine signaling and are involved in the control of cellular growth. As a non-receptor kinase, Jak 2 has a cytoplasmic enzyme which catalyzes the transfer of a phosphate group through phosphorylation to the tyrosine residue in the protein. Such an enzyme plays a crucial role in regulating various cellular functions by switching on or off additional enzymes within the cell. <ref> Hanks, SK., Quinn, AM., Hunter, T. (1988). The protein kinase family: conserved features and deduced phylogeny of the catalytic domains. Science 241 (4861): 42–52. doi:10.1126/science.3291115. PMID 3291115. </ref> Such phosphorylation is a reversible process, and used in many different pathways as a method to control cellular activity. However kinases like Jak2, have enzymes which add phosphate groups to hydroxyl side chains as can be seen in the diagram. <ref> Hudel, H. [Internet]. Irvine [CA]. Center for Biomembrane Systems at UC Irvine; c2013. [Updated 2013 Jan 3; cited 2013 March 23]. Available from: http://bass.bio.uci.edu </ref> | Janus Kinase 2 is a non-receptor janus kinase, a protein which is part of the tyrosine kinases. These group of kinases are the primary intracellular mediators of cytokine signaling and are involved in the control of cellular growth. As a non-receptor kinase, Jak 2 has a cytoplasmic enzyme which catalyzes the transfer of a phosphate group through phosphorylation to the tyrosine residue in the protein. Such an enzyme plays a crucial role in regulating various cellular functions by switching on or off additional enzymes within the cell. <ref> Hanks, SK., Quinn, AM., Hunter, T. (1988). The protein kinase family: conserved features and deduced phylogeny of the catalytic domains. Science 241 (4861): 42–52. doi:10.1126/science.3291115. PMID 3291115. </ref> Such phosphorylation is a reversible process, and used in many different pathways as a method to control cellular activity. However kinases like Jak2, have enzymes which add phosphate groups to hydroxyl side chains as can be seen in the diagram. <ref> Hudel, H. [Internet]. Irvine [CA]. Center for Biomembrane Systems at UC Irvine; c2013. [Updated 2013 Jan 3; cited 2013 March 23]. Available from: http://bass.bio.uci.edu </ref> | ||
Jak2 was given its name "Janus" after the two-faced Roman God "Janus" who was known as the custodian of the universe and the God of new beginnings. <ref> Janus incarnate [Internet]. Kirwan Studios; c2011. [Updated 2011 Feb 3; cited 2013 March 23' Retrieved from http://rense.com/general92/janus.htm http://rense.com/general92/janus.htm </ref> The abbreviation 'Jak' is commonly referred to as 'just another kinase' as, when it was first discovered, the kinase's role was not yet fully understood. <ref> Weinberg, I. (April 2010). Janus Kinase (Jak2)”. Vascular Medicind; Angiolgist http://www.angiologist.com/general-medicine/janus-kinase-2-jak2/ </ref> | Jak2 was given its name "Janus" after the two-faced Roman God "Janus" who was known as the custodian of the universe and the God of new beginnings. <ref> Janus incarnate [Internet]. Kirwan Studios; c2011. [Updated 2011 Feb 3; cited 2013 March 23' Retrieved from http://rense.com/general92/janus.htm http://rense.com/general92/janus.htm </ref> The abbreviation 'Jak' is commonly referred to as 'just another kinase' as, when it was first discovered, the kinase's role was not yet fully understood. <ref> Weinberg, I. (April 2010). Janus Kinase (Jak2)”. Vascular Medicind; Angiolgist http://www.angiologist.com/general-medicine/janus-kinase-2-jak2/ </ref> | ||
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== Analyzing and Discovering Jak2 Structure == | == Analyzing and Discovering Jak2 Structure == | ||
In determining the three-dimensional structure of the Jak2 protein, three primary methods of analysis were used; protein expression and purification, crystallization, and x-ray data collection. <ref> Lucet, I., Fantino, E., & Styles, M. (2005). The structural basis of janus kinase 2 inhibition by a potent and specific pan-janus kinase inhibitor. Blood, 107, 176-183. doi: 10.1182/blood-2005-06-2413 http://bloodjournal.hematologylibrary.org/content/107/1/176.full.pdf </ref> In the protein expression and purification the Jak2 residue was cloned using pFastBac which uses “two promoters in a single vector for expression of two proteins simultaneously in insect cells”. <ref> http://www.invitrogen.com/1/1/14896-pfastbac-dual.html </ref> The bacmid DNA with the kinase insert was then isolated and put into cells of insect army worms. The cells were then grown, lysed and centrifuged after which the protein was then incubated, separated with gel filtration and fractions were taken for crystallization trials. In these crystallization trials, the protein residue was used to grow crystals via hanging drop vapor-diffusion. The purified protein complex was then mixed with solutions which subsequently formed crystals after one to three days. The crystalized protein was then flash frozen and the structure determined via molecular replacement and the AmoRe program. <ref> ) Lucet, I., Fantino, E., & Styles, M. (2005). The structural basis of janus kinase 2 inhibition by a potent and specific pan-janus kinase inhibitor. Blood, 107, 176-183. doi: 10.1182/blood-2005-06-2413 http://bloodjournal.hematologylibrary.org/content/107/1/176.full.pdf </ref> | In determining the three-dimensional structure of the Jak2 protein, three primary methods of analysis were used; protein expression and purification, crystallization, and x-ray data collection. <ref> Lucet, I., Fantino, E., & Styles, M. (2005). The structural basis of janus kinase 2 inhibition by a potent and specific pan-janus kinase inhibitor. Blood, 107, 176-183. doi: 10.1182/blood-2005-06-2413 http://bloodjournal.hematologylibrary.org/content/107/1/176.full.pdf </ref> In the protein expression and purification the Jak2 residue was cloned using pFastBac which uses “two promoters in a single vector for expression of two proteins simultaneously in insect cells”. <ref> pFastbac Duo [Internet]. Life Technologies Corporation; c2013. [Updated 2013; cited 2013 March 23]. Available from: http://www.invitrogen.com/1/1/14896-pfastbac-dual.html </ref> The bacmid DNA with the kinase insert was then isolated and put into cells of insect army worms. The cells were then grown, lysed and centrifuged after which the protein was then incubated, separated with gel filtration and fractions were taken for crystallization trials. In these crystallization trials, the protein residue was used to grow crystals via hanging drop vapor-diffusion. The purified protein complex was then mixed with solutions which subsequently formed crystals after one to three days. The crystalized protein was then flash frozen and the structure determined via molecular replacement and the AmoRe program. <ref> ) Lucet, I., Fantino, E., & Styles, M. (2005). The structural basis of janus kinase 2 inhibition by a potent and specific pan-janus kinase inhibitor. Blood, 107, 176-183. doi: 10.1182/blood-2005-06-2413 http://bloodjournal.hematologylibrary.org/content/107/1/176.full.pdf </ref> | ||
<Structure load='2b7a' size='350' frame='true' align='right' caption='3-D Structure of Jak2 as created in Protein Data Bank' scene='Insert optional scene name here' /> | <Structure load='2b7a' size='350' frame='true' align='right' caption='3-D Structure of Jak2 as created in Protein Data Bank' scene='Insert optional scene name here' /> | ||
