Background information
The protein encoded by this gene is a dual specificity protein kinase that belongs to the MAP kinase kinase family. This kinase specifically activates MAPK8/JNK1 and MAPK9/JNK2, and this kinase itself is phosphorylated and activated by MAP kinase kinase kinases including MAP3K1/MEKK1, MAP3K2/MEKK2,MAP3K3/MEKK5, and MAP4K2/GCK. This kinase is involved in the signal transduction mediating the cell responses to proinflammatory cytokines, and environmental stresses. Multiple alternatively spliced transcript variants encoding distinct isoforms have been found, but only one transcript variant has been supported and defined. [provided by RefSeq]. Hsp27, also referred to as the Estrogen regulated 24K protein and HSP28, is one of several small heat shock proteins (HSP) produced by all organisms studied. Hsp27 synthesis is induced by elevated temperature, as well as estrogen in hormone responsive cells. This protein is involved in stress resistance and actin organization. Interestingly, human HSP27 also shares greater than 50% homology with low molecular weight Drosophila HSP's and mammalian a-crystalline lens protein. Because of the estrogen responsive nature of Hsp27, this protein has been studied extensively in human estrogen responsive tissues such as cervix, endometrium and breast tissue. This work has led to the suggestion that Hsp27 may be a useful marker in classifying various hormone sensitive tumors.
