Mxi2, a Mitogen-Activated Protein Kinase that Recognizes and Phosphorylates Max Protein

• Published in: Proceedings of the National Academy of Sciences - PNAS 1995-11, Vol.92 (23), p.10531-10534
• Main Authors: Zervos, Antonis S., Faccio, Lucia, Gatto, Joseph P., Kyriakis, John M., Brent, Roger
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Amino acids; Base Sequence; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; Basic-Leucine Zipper Transcription Factors; Biochemistry; Calcium-Calmodulin-Dependent Protein Kinases - genetics; Calcium-Calmodulin-Dependent Protein Kinases - metabolism; Complementary DNA; COS cells; DNA; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Genetics; Helix-Loop-Helix Motifs; Human genetics; Humans; Mitogen-Activated Protein Kinases; Molecular Sequence Data; Myelin basic proteins; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Plasmids; Polymerase Chain Reaction; Protein Binding; Proteins; Proto-Oncogene Proteins c-myc - genetics; Sequence Analysis, DNA; Transcription Factors; Yeasts
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.92.23.10531

We describe Mxi2, a human protein that interacts with Max protein, the heterodimeric partner of the Myc oncoprotein. Mxi2 encodes a 297-residue protein whose sequence indicates that it is related to extracellular signal-regulated kinases (ERK protein kinases). Mxi2 in yeast interacts with Max and with the C terminus of c-Myc. Mxi2 phosphorylates Max both in vitro and in vivo. The Mxi2 putative substrate recognition region has sequence similarity to the helix-loop-helix region in Max and c-Myc, suggesting that substrate recognition might be mediated via this motif. Phosphorylation by Mxi2 may affect the ability of Max to oligomerize with itself and its partners, bind DNA, or regulate gene expression.