What is the Difference Between p38 MAPK and ERK?

The main difference between p38 MAPK and ERK lies in their responsiveness to different stimuli and their respective functions in cellular processes. Here are the key distinctions between the two:

1. Stimuli: p38 MAPK is responsive to stress stimuli such as cytokines, ultraviolet irradiation, heat shock, and osmotic shock. In contrast, ERK is activated by stimuli such as growth factors, cytokines, virus infection, ligands for heterotrimeric G protein-coupled receptors, transforming agents, and carcinogens.
2. Functions: p38 MAPK plays a role in regulating cell differentiation, apoptosis, and autophagy. On the other hand, ERK is involved in regulating meiosis, mitosis, and postmitotic functions.
3. Substrates: While both p38 MAPK and ERK activate MAPK-activated protein kinases (MAPKAPKs), specific subfamilies of ERK1/2 substrates are exclusively activated by the ERKs, such as ribosomal s6 kinases (RSKs). p38 MAPK, on the other hand, has different substrates, including mitogen- and stress-activated protein kinases (MSKs) and MAP kinase-interacting serine/threonine-protein kinases (MNKs).

Despite their differences, both p38 MAPK and ERK are part of the mitogen-activated protein kinase (MAPK) pathway, which plays a crucial role in cell proliferation, differentiation, motility, and survival.

Comparative Table: p38 MAPK vs ERK

Here is a table comparing the differences between p38 MAPK and ERK:

p38 MAPK and ERK are both involved in the regulation of cellular processes, but they are activated by different stimuli and have distinct functions. p38 MAPK is mainly involved in regulating cell differentiation, apoptosis, and autophagy, while ERK is involved in regulating meiosis, mitosis, and postmitotic functions in differentiated cells.