Developmental Biology

The Stress of Erythropoiesis

Science's STKE  25 Jul 2000:
Vol. 2000, Issue 42, pp. tw3
DOI: 10.1126/stke.2000.42.tw3

It has been thought that the major function of p38, a stress-activated protein kinase of the MAP kinase family, is to activate stress responses during inflammation. However, Tamura et al. report that when mice lack p38α, those that survive are anemic and display defective erythropoiesis. P38α-deficent mice had fewer proerythroblasts and mature erythroid cells than their wild-type counterparts. Although p38α is thought to act downstream of receptors for certain hematopoietic growth factors such as erythropoietin (Epo), the phenotype of the p38α-deficient mice appeared most similar to that of Epo-deficient mice. The authors discovered a decrease in Epo mRNA in p38α-deficient mice and propose that p38α acts posttranscriptionally to stabilize Epo mRNA. Given that p38α is activated in certain cells subjected to hypoxia, and given that embryos may be subjected to mild hypoxia during development, it may be that p38α provides a link between stress-induced erythropoiesis and developmental erythropoeisis.

Tamura, K., Sudo, T., Senftleben, U., Dadak, A.M., Johnson, R., and Karin, M. (2000) Requirement for p38α in erythropoietin expression: A role for stress kinases in erythropoiesis. Cell 102: 221-231. [Online Journal]