title: Heterotypic complex formation between subunits of microtubule-associated proteins 1A and 1B is due to interaction of conserved domains.
abstract: The microtubule-associated proteins MAP1A and MAP1B are related but distinct multi-subunit protein complexes that consist of heavy and light chains. The predominant forms of these complexes are homotypic, i.e. they consist of a MAP1A heavy chain associated with MAP1A light chains or a MAP1B heavy chain associated with MAP1B light chains, respectively. In addition, MAP1A and MAP1B can exchange subunits and form heterotypic complexes consisting of a MAP1A heavy chain associated with MAP1B light chains which might play a role in a transition period of neuronal differentiation. Here we extend previous findings by confirming that heterotypic MAP1B heavy chain-MAP1A light chain complexes also exist in the developing murine brain. We show that these complexes form through interaction of homologous domains conserved in heavy and light chains of MAP1A and MAP1B. Likewise, conserved domains of the MAP1A and MAP1B light chains account for formation of light chain heterodimers. By yeast 2-hybrid analysis we located the light chain binding domain on the heavy chain to amino acids 211-508, thereby defining a new functional subdomain.
authors.affiliation: Max F. Perutz Laboratories, Department of Molecular Cell Biology, University of Vienna, Dr. Bohr-Gasse 9, A-1030 Vienna, Austria, Europe.
authors.forename: Rainer
authors.initials: R
authors.lastname: Noiges
authors.forename: Heike
authors.initials: H
authors.lastname: Stroissnigg
authors.forename: Alzbeta
authors.initials: A
authors.lastname: Tranciková
authors.forename: Ilse
authors.initials: I
authors.lastname: Kalny
authors.forename: René
authors.initials: R
authors.lastname: Eichinger
authors.forename: Friedrich
authors.initials: F
authors.lastname: Propst
mesh_terms: D000818:Animals; D002460:Cell Line; D017124:Conserved Sequence; D019281:Dimerization; D008869:Microtubule-Associated Proteins / Q000737:chemistry* / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D011485:Protein Binding; D021122:Protein Subunits / Q000737:chemistry*; D051381:Rats; D013329:Structure-Activity Relationship; D014162:Transfection
chemical_list: D008869:Microtubule-Associated Proteins; D021122:Protein Subunits; C085284:microtubule-associated protein 1B