Protein kinase A phosphorylates serine 267 in the homeodomain of engrailed-2 leading to decreased DNA binding.
Engrailed-2 (En-2) belongs to an evolutionarily conserved family of DNA binding homeodomain-containing proteins that are expressed in mammalian brain during development. Here, we demonstrate that serine 267 in the homeodomain of En-2 is phosphorylated by protein kinase A (PKA) in forskolin-treated COS-7 cells. Furthermore, we analyze the physiological function of En-2 phosphorylation by PKA. The nuclear localization of En-2 is not influenced by the phosphorylation of serine 267. However, substitution of serine 267 with alanine resulted in increased binding of En-2 to DNA, while replacing serine 267 with glutamic acid resulted in decreased En-2 DNA binding. These results suggest that the transcriptional activity of En-2 is regulated by PKA.
Hjerrild
Majbrit
M
Department of Clinical Biochemistry, Glostrup Hospital, Nordre Ringvej, DK-2600 Glostrup, Denmark. mh@dcb-glostrup.dk
Stensballe
Allan
A
Jensen
Ole N
ON
Gammeltoft
Steen
S
Rasmussen
Thomas E
TE
D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002467:Cell Nucleus / Q000201:enzymology / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000737:chemistry / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D000099266:Engrailed 2 Protein
D017868:Cyclic AMP-Dependent Protein Kinases; D004247:DNA; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D000099266:Engrailed 2 Protein