27
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: not found
      • Article: not found

      Functional activity of myogenic HLH proteins requires hetero-oligomerization with E12/E47-like proteins in vivo

      Cell
      Elsevier BV

      Read this article at

      ScienceOpenPublisher
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Related collections

          Most cited references42

          • Record: found
          • Abstract: found
          • Article: not found

          A new DNA binding and dimerization motif in immunoglobulin enhancer binding, daughterless, MyoD, and myc proteins.

          Two cDNAs were isolated whose dimerized products bind specifically to a DNA sequence, kappa E2, located in the immunoglobulin kappa chain enhancer. Both cDNAs share a region of extensive identity to the Drosophila daughterless gene and obvious similarity to a segment in three myc proteins, MyoD, and members of the Drosophila achaete-scute and twist gene family. The homologous regions have the potential to form two amphipathic helices separated by an intervening loop. Remarkable is the stringent conservation of hydrophobic residues present in both helices. We demonstrate that this new motif plays a crucial role in both dimerization and DNA binding.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Interactions between heterologous helix-loop-helix proteins generate complexes that bind specifically to a common DNA sequence.

            A DNA binding and dimerization motif, with apparent amphipathic helices (the HLH motif), has recently been identified in various proteins, including two that bind to immunoglobulin enhancers (E12 and E47). We show here that various HLH proteins can bind as apparent heterodimers to a single DNA motif and also, albeit usually more weakly, as apparent homodimers. The HLH domain can mediate heterodimer formation between either daughterless, E12, or E47 (Class A) and achaete-scute T3 or MyoD (Class B) to form proteins with high affinity for the kappa E2 site in the immunoglobulin kappa chain enhancer. The achaete-scute T3 and MyoD proteins do not form kappa E2-binding heterodimers together, and no active complex with N-myc was evident. The formation of a heterodimer between the daughterless and achaete-scute T3 products may explain the similar phenotypes of mutants at these two loci and the genetic interactions between them. A role of E12 and E47 in mammalian development, analogous to that of daughterless in Drosophila, is likely.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Max: a helix-loop-helix zipper protein that forms a sequence-specific DNA-binding complex with Myc.

              The myc protooncogene family has been implicated in cell proliferation, differentiation, and neoplasia, but its mechanism of function at the molecular level is unknown. The carboxyl terminus of Myc family proteins contains a basic region helix-loop-helix leucine zipper motif (bHLH-Zip), which has DNA-binding activity and has been predicted to mediate protein-protein interactions. The bHLH-Zip region of c-Myc was used to screen a complementary DNA (cDNA) expression library, and a bHLH-Zip protein, termed Max, was identified. Max specifically associated with c-Myc, N-Myc, and L-Myc proteins, but not with a number of other bHLH, bZip, or bHLH-Zip proteins. The interaction between Max and c-Myc was dependent on the integrity of the c-Myc HLH-Zip domain, but not on the basic region or other sequences outside the domain. Furthermore, the Myc-Max complex bound to DNA in a sequence-specific manner under conditions where neither Max nor Myc exhibited appreciable binding. The DNA-binding activity of the complex was dependent on both the dimerization domain and the basic region of c-Myc. These results suggest that Myc family proteins undergo a restricted set of interactions in the cell and may belong to the more general class of eukaryotic DNA-binding transcription factors.
                Bookmark

                Author and article information

                Journal
                10.1016/0092-8674(91)90620-E
                http://www.elsevier.com/tdm/userlicense/1.0/

                Comments

                Comment on this article