Evidence against structural and functional identity of microtubule-associated protein 1B and proteoglycan claustrin.
Recently, the concept of microtubule-associated protein 1B as an intracellular 2460 amino acid protein was challenged by the suggestion that only the N-terminal 1022 codons are utilized and encode the core protein of the extracellular proteoglycan claustrin (Burg and Cole (1994) J. Neurobiol. 25, 1-22). We expressed this N-terminal MAP1B fragment in tissue culture cells and found that it bound to microtubules and was not localized in the extracellular matrix. In addition, epitope mapping demonstrated that MAP1B consisted of more than 1022 amino acids and that the reported cDNA of claustrin is incomplete.
Tögel
M
M
Institute of Biochemistry and Molecular Cell Biology, Vienna Biocenter, University of Vienna, Austria.
Wiche
G
G
Propst
F
F
D016475:3T3 Cells; D000818:Animals; D001921:Brain / Q000166:cytology; D011508:Chondroitin Sulfate Proteoglycans / Q000737:chemistry / Q000235:genetics*; D007632:Keratan Sulfate / Q000737:chemistry / Q000235:genetics*; D000071234:Lumican; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D008870:Microtubules / Q000378:metabolism; D011509:Proteoglycans / Q000235:genetics*; D051381:Rats; D014407:Tumor Cells, Cultured / Q000378:metabolism
D011508:Chondroitin Sulfate Proteoglycans; C000604307:Lum protein, mouse; C000604308:Lum protein, rat; D000071234:Lumican; D008869:Microtubule-Associated Proteins; D011509:Proteoglycans; C085284:microtubule-associated protein 1B; D007632:Keratan Sulfate