title: Fusion protein Isl1-Lhx3 specifies motor neuron fate by inducing motor neuron genes and concomitantly suppressing the interneuron programs.
abstract: Combinatorial transcription codes generate the myriad of cell types during development and thus likely provide crucial insights into directed differentiation of stem cells to a specific cell type. The LIM complex composed of Isl1 and Lhx3 directs the specification of spinal motor neurons (MNs) in embryos. Here, we report that Isl1-Lhx3, a LIM-complex mimicking fusion, induces a signature of MN transcriptome and concomitantly suppresses interneuron differentiation programs, thereby serving as a potent and specific inducer of MNs in stem cells. We show that an equimolar ratio of Isl1 and Lhx3 and the LIM domain of Lhx3 are crucial for generating MNs without up-regulating interneuron genes. These led us to design Isl1-Lhx3, which maintains the desirable 1:1 ratio of Isl1 and Lhx3 and the LIM domain of Lhx3. Isl1-Lhx3 drives MN differentiation with high specificity and efficiency in the spinal cord and embryonic stem cells, bypassing the need for sonic hedgehog (Shh). RNA-seq analysis revealed that Isl1-Lhx3 induces the expression of a battery of MN genes that control various functional aspects of MNs, while suppressing key interneuron genes. Our studies uncover a highly efficient method for directed MN generation and MN gene networks. Our results also demonstrate a general strategy of using embryonic transcription complexes for producing specific cell types from stem cells.
authors.affiliation: Neuroscience Section, Department of Pediatrics, Papé Family Pediatric Research Institute, Oregon Health and Science University, Portland, OR 97239, USA.
authors.forename: Seunghee
authors.initials: S
authors.lastname: Lee
authors.forename: James M
authors.initials: JM
authors.lastname: Cuvillier
authors.forename: Bora
authors.initials: B
authors.lastname: Lee
authors.forename: Rongkun
authors.initials: R
authors.lastname: Shen
authors.forename: Jae W
authors.initials: JW
authors.lastname: Lee
authors.forename: Soo-Kyung
authors.initials: SK
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D045744:Cell Line, Tumor; D019070:Cell Lineage; D002478:Cells, Cultured; D002642:Chick Embryo; D053595:Embryonic Stem Cells / Q000166:cytology; D018507:Gene Expression Regulation, Developmental; D007395:Interneurons / Q000166:cytology; D060850:LIM-Homeodomain Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008969:Molecular Sequence Data; D009046:Motor Neurons / Q000166:cytology*; D032446:Myoblasts / Q000166:cytology; D054259:Neural Tube / Q000166:cytology / Q000187:drug effects; D055495:Neurogenesis / Q000235:genetics / Q000502:physiology*; D017434:Protein Structure, Tertiary; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000502:physiology; D016415:Sequence Alignment; D013116:Spinal Cord / Q000166:cytology / Q000196:embryology; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D059467:Transcriptome
chemical_list: D060850:LIM-Homeodomain Proteins; C094898:Lhx3 protein; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C063843:insulin gene enhancer binding protein Isl-1