Microtubule associated protein 2 (MAP2) interacts with the regulatory protein 14-3-3ζ in a cAMP-dependent protein kinase (PKA) phosphorylation dependent manner. Using selective phosphorylation, calorimetry, nuclear magnetic resonance, chemical crosslinking, and X-ray crystallography, we characterized interactions of 14-3-3ζ with various binding regions of MAP2c. Although PKA phosphorylation increases the affinity of MAP2c for 14-3-3ζ in the proline rich region and C-terminal domain, unphosphorylated MAP2c also binds the dimeric 14-3-3ζ via its microtubule binding domain and variable central domain. Monomerization of 14-3-3ζ leads to the loss of affinity for the unphosphorylated residues. In neuroblastoma cell extract, MAP2c is heavily phosphorylated by PKA and the proline kinase ERK2. Although 14-3-3ζ dimer or monomer do not interact with the residues phosphorylated by ERK2, ERK2 phosphorylation of MAP2c in the C-terminal domain reduces the binding of MAP2c to both oligomeric variants of 14-3-3ζ.

• Keywords
• 14‐3‐3 proteins, extracellular signal‐regulated kinase 2, microtubule‐associated protein, nuclear magnetic resonance, protein kinase A,
• MeSH
• Phosphorylation MeSH
• Crystallography, X-Ray MeSH
• Humans MeSH
• Mitogen-Activated Protein Kinase 1 metabolism   genetics   MeSH
• Models, Molecular MeSH
• Protein Multimerization MeSH
• Cyclic AMP-Dependent Protein Kinases metabolism   genetics   MeSH
• 14-3-3 Proteins * metabolism   chemistry   genetics   MeSH
• Microtubule-Associated Proteins * metabolism   chemistry   genetics   MeSH
• Protein Binding MeSH
• Binding Sites MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• MAPK1 protein, human MeSH Browser
• Mitogen-Activated Protein Kinase 1 MeSH
• Cyclic AMP-Dependent Protein Kinases MeSH
• 14-3-3 Proteins * MeSH
• Microtubule-Associated Proteins * MeSH
• YWHAZ protein, human MeSH Browser

Isoforms of microtubule-associated protein 2 (MAP2) differ from their homolog Tau in the sequence and interactions of the N-terminal region. Binding of the N-terminal region of MAP2c (N-MAP2c) to the dimerization/docking domains of the regulatory subunit RIIα of cAMP-dependent protein kinase (RIIDD2) and to the Src-homology domain 2 (SH2) of growth factor receptor-bound protein 2 (Grb2) have been described long time ago. However, the structural features of the complexes remained unknown due to the disordered nature of MAP2. Here, we provide structural description of the complexes. We have solved solution structure of N-MAP2c in complex with RIIDD2, confirming formation of an amphiphilic α-helix of MAP2c upon binding, defining orientation of the α-helix in the complex and showing that its binding register differs from previous predictions. Using chemical shift mapping, we characterized the binding interface of SH2-Grb2 and rat MAP2c phosphorylated by the tyrosine kinase Fyn in their complex and proposed a model explaining differences between SH2-Grb2 complexes with rat MAP2c and phosphopeptides with a Grb2-specific sequence. The results provide the structural basis of a potential role of MAP2 in regulating cAMP-dependent phosphorylation cascade via interactions with RIIDD2 and Ras signaling pathway via interactions with SH2-Grb2.

• Keywords
• A-kinase anchoring protein (AKAP), growth factor receptor-bound protein 2 (GRB2), microtubule associated protein (MAP) 2, nuclear magnetic resonance (NMR), protein kinase A (PKA),
• MeSH
• GRB2 Adaptor Protein * metabolism   chemistry   MeSH
• Humans MeSH
• Protein Domains MeSH
• Microtubule-Associated Proteins * metabolism   chemistry   genetics   MeSH
• Proto-Oncogene Proteins c-fyn metabolism   chemistry   genetics   MeSH
• Signal Transduction MeSH
• src Homology Domains MeSH
• Protein Binding * MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• GRB2 Adaptor Protein * MeSH
• GRB2 protein, human MeSH Browser
• Microtubule-Associated Proteins * MeSH
• Proto-Oncogene Proteins c-fyn MeSH