What Is a P38 Pathway?

p38 MAPK was discovered in 1993 by Brewster et al. when studying the effects of hypertonic environments on fungi. It was later found that it also exists in mammalian cells and is also one of the subclasses of MAPKs. Its properties are similar to JNK, and they are also stress-activated protein kinases. At present, there are 5 isomers of p38MAPK, which are p38 (p38), p381, p382, p38, and p38. Its distribution is tissue-specific: p38, p381, p382 are widely present in various tissue cells, p38 is only present in skeletal muscle cells, and p38 is mainly present in glandular tissues. Studies have confirmed that activators of the p38MAPK pathway are similar to the JNK pathway. Some pro-inflammatory factors (TNF, IL-1) and stress stimuli (UV, H2O2, heat shock, hypertonicity and protein synthesis inhibitors) that can activate JNK can also activate p38. In addition, p38 can be activated by lipopolysaccharide and G + Activated by bacterial cell wall components. The p38 signaling pathway is also composed of a tertiary kinase chain. Its upstream activators are MKK3, MKK4, and MKK6. Unlike MKK4, MKK3 and MKK6 only specifically activate p38 [9]. In vitro cell transfection experiments showed that MEKK2. MEKK3 can activate both JNK and p38 by activating MKK4, while MEKK3 specifically activates p38 by activating MKK3. Different p38 isomers can have different responses to the same stimulus. IL-1 activates p38 significantly more than p38, and TNF1- makes the time for p38 activity to peak significantly shorter than the time for p38 to peak [10]. Different isomers are also selective for substrates. P38 2 phosphorylates ATF2 significantly better than p38. P38 can phosphorylate ATF2, but it cannot activate MAPKAP-K2 and MAPKAP-K3 [11]; Isomers are coupled to different upstream kinases. MKK6 can activate p38, p382, and p38, while MKK3 can only activate p38 and p38.