Characterization of the targeting, binding, and phosphorylation site domains of an A kinase anchor protein and a myristoylated alanine-rich C kinase substrate-like analog that are encoded by a single gene.
A novel Drosophila A kinase anchor protein, Drosophila A kinase anchor protein 200 (DAKAP200), is predicted to be involved in routing, mediating, and integrating signals carried by cAMP, Ca(2+), and diacylglycerol (Li, Z., Rossi, E. A., Hoheisel, J. D., Kalderon, D., and Rubin, C. S. (1999) J. Biol. Chem. 274, 27191-27200). Experiments designed to assess this hypothesis now (a) establish the function, boundaries and identity of critical amino acids of the protein kinase AII (PKAII) tethering site of DAKAP200; (b) demonstrate that residues 119-148 mediate binding with Ca(2+)-calmodulin and F-actin; (c) show that a polybasic region of DAKAP200 is a substrate for protein kinase C; (d) reveal that phosphorylation of the polybasic domain regulates affinity for F-actin and Ca(2+)-calmodulin; and (e) indicate that DAKAP200 is myristoylated and that this modification promotes targeting of DAKAP200 to plasma membrane. DeltaDAKAP200, a second product of the DAKAP200 gene, cannot tether PKAII. However, DeltaDAKAP200 is myristoylated and contains a phosphorylation site domain that binds Ca(2+)-calmodulin and F-actin. An atypical amino acid composition, a high level of negative charge, exceptional thermostability, unusual hydrodynamic properties, properties of the phosphorylation site domain, and a calculated M(r) of 38,000 suggest that DeltaDAKAP200 is a new member of the myristoylated alanine-rich C kinase substrate protein family. DAKAP200 is a potentially mobile, chimeric A kinase anchor protein-myristoylated alanine-rich C kinase substrate protein that may facilitate localized reception and targeted transmission of signals carried by cAMP, Ca(2+), and diacylglycerol.
Rossi
E A
EA
Department of Molecular Pharmacology, Atran Laboratories, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
Li
Z
Z
Feng
H
H
Rubin
C S
CS
D054758:A Kinase Anchor Proteins; D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002645:Chickens; D000242:Cyclic AMP / Q000378:metabolism; D029721:Drosophila Proteins; D004331:Drosophila melanogaster; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D010449:Peptide Mapping; D010766:Phosphorylation; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013329:Structure-Activity Relationship
D054758:A Kinase Anchor Proteins; D048868:Adaptor Proteins, Signal Transducing; C121679:Akap200 protein, Drosophila; D002352:Carrier Proteins; D029721:Drosophila Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D011506:Proteins; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D000242:Cyclic AMP; D011493:Protein Kinase C; D002118:Calcium