Differentiate between ERK and JNK

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mp241186's picture
Differentiate between ERK and JNK

Hi everyone,
I am new  student  instudying  cell signalling and signal  transduction. I still cannot realize the minute diffference between ERK and JNK ? Can please someone help me out.
Thanking you in advance .

Jitendra Sinha
Jitendra Sinha's picture
ERK and JNK are separate

ERK and JNK are separate types of MAPKinases. You can go through a 2004 BMC paper on activation of these pathways in rat brain at http://www.biomedcentral.com/1471-2202/5/36
Another paper http://dev.biologists.org/cgi/content/full/134/6/1203 Chambon et al., where they talk about ERK- and JNK-signalling to regulate the gene networks that stimulate metamorphosis and apoptosis in tail tissues of ascidian tadpoles.

Ivan Delgado
Ivan Delgado's picture

Hi mp241186,
As you likely know the three known MAPK signaling pathways, ERK 1/2, JNK/SAPK (and p38), are so named just because of the MAPK that was originally associated with it. They all follow the same cascade: activation of MEKK, which then phosphorylates and activates MEK, which in turn phosphorylates and activates MAPK. As it is understood today, and in very general terms, the difference between these signaling cascades is in the stimulus required to activate them. ERK 1/2 is activated by extracellular stimuli (proliferation/differentiation), while JNK/SAPK (and p38) is activated by stress.
Once you get beyond this generalization it gets a lot more complicated since each one of these pathways is likely going to be regulated in a different manner in different situations/locations. This is specially true when you start including the phosphatases.
A good place to look at these pathways is www.cellsignaling.com.