Disparate binding kinetics by an intrinsically disordered domain enables temporal regulation of transcriptional complex formation
| Autor: | Neil O. Robertson, Ngaio C. Smith, Jacqueline M. Matthews, Athina Manakas, Mahiar Mahjoub, Gordon McDonald, Ann H. Kwan |
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| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
LIM-Homeodomain Proteins Intrinsically disordered proteins Protein–protein interaction Mice 03 medical and health sciences Protein Domains Animals Transcription factor Ternary complex Transcription Initiation Genetic LIM domain Multidisciplinary Chemistry DNA Protein engineering Biological Sciences LIM Domain Proteins Receptor–ligand kinetics DNA-Binding Proteins Intrinsically Disordered Proteins body regions Kinetics 030104 developmental biology Multiprotein Complexes Biophysics LHX3 Protein Binding Transcription Factors |
| Zdroj: | Proceedings of the National Academy of Sciences. 115:4643-4648 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.1714646115 |
| Popis: | Intrinsically disordered regions are highly represented among mammalian transcription factors, where they often contribute to the formation of multiprotein complexes that regulate gene expression. An example of this occurs with LIM-homeodomain (LIM-HD) proteins in the developing spinal cord. The LIM-HD protein LHX3 and the LIM-HD cofactor LDB1 form a binary complex that gives rise to interneurons, whereas in adjacent cell populations, LHX3 and LDB1 form a rearranged ternary complex with the LIM-HD protein ISL1, resulting in motor neurons. The protein–protein interactions within these complexes are mediated by ordered LIM domains in the LIM-HD proteins and intrinsically disordered LIM interaction domains (LIDs) in LDB1 and ISL1; however, little is known about how the strength or rates of binding contribute to complex assemblies. We have measured the interactions of LIM:LID complexes using FRET-based protein–protein interaction studies and EMSAs and used these data to model population distributions of complexes. The protein–protein interactions within the ternary complexes are much weaker than those in the binary complex, yet surprisingly slow LDB1:ISL1 dissociation kinetics and a substantial increase in DNA binding affinity promote formation of the ternary complex over the binary complex in motor neurons. We have used mutational and protein engineering approaches to show that allostery and modular binding by tandem LIM domains contribute to the LDB1 LID binding kinetics. The data indicate that a single intrinsically disordered region can achieve highly disparate binding kinetics, which may provide a mechanism to regulate the timing of transcriptional complex assembly. |
| Databáze: | OpenAIRE |
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