Microtubule-associated protein MAP2 shares a microtubule binding motif with tau protein.
The microtubule-associated protein MAP2 is a prominent large-sized component of purified brain microtubules that, like the 36- to 38-kilodalton tau proteins, bears antigenic determinants found in association with the neurofibrillary tangles of Alzheimer's disease. The complete sequence of mouse brain MAP2 was determined from a series of overlapping cloned complementary DNAs. The sequence of the carboxyl-terminal 185 amino acids is very similar (67 percent) to a corresponding region of tau protein, and includes a series of three imperfect repeats, each 18 amino acids long and separated by 13 or 14 amino acids. A subcloned fragment spanning the first two of the 18-amino acid repeats was expressed as a polypeptide by translation in vitro. This polypeptide copurified with microtubules through two successive cycles of polymerization and depolymerization, whereas a control polypeptide derived from the amino-terminal region of MAP2 completely failed to copurify. These data imply that the carboxyl-terminal domain containing the 18-amino acid repeats constitutes the microtubule binding site in MAP2. The occurrence of these repeats in tau protein suggests that these may be a general feature of microtubule binding proteins.
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D004247:DNA / Q000235:genetics; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009419:Nerve Tissue Proteins; D014176:Protein Biosynthesis; D012091:Repetitive Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid; D014404:Tubulin / Q000378:metabolism; D016875:tau Proteins
D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; D014404:Tubulin; D016875:tau Proteins; D004247:DNA