ISL1
Description
The ISL1 (ISL LIM homeobox 1) is a protein-coding gene located on chromosome 5.
ISL1 (Insulin gene enhancer protein ISL-1) is a transcription factor encoded by the ISL1 gene in humans. It contains two N-terminal LIM domains and one C-terminal homeodomain. ISL1 plays a vital role in the embryogenesis of pancreatic islets of Langerhans, and its deficiency in mouse embryos leads to failure of neural tube motor neuron differentiation. ISL1 interacts with Estrogen receptor alpha and is a marker for cardiac progenitors of the secondary heart field (SHF), which contributes to the right ventricle and the outflow tract. ISL1's function is essential for the proliferation, survival, and migration of cardiogenic precursors, and its deficiency leads to severe cardiac defects. Research has indicated that ISL1 can promote the differentiation of cardiac cells, and its depletion can alter the fate of developing cardiomyocytes, potentially switching them from a ventricular to an atrial identity. However, the validity of ISL1 as a marker for cardiac progenitor cells has been questioned due to conflicting findings.
ISL1 is a DNA-binding transcriptional activator that binds to the octamer sequence 5'-ATAATTAA-3' in the promoters of its target genes. It plays a crucial role in the gene regulatory network that controls retinal ganglion cell (RGC) differentiation, cooperating with the transcription factor POU4F2 to maximize RGC gene expression and ensure proper RGC development in the retina. ISL1 is also involved in motor neuron specification, working in conjunction with LHX3 and LDB1. Additionally, it binds to insulin gene enhancer sequences and is essential for heart development. ISL1 marks a specific progenitor cell population responsible for generating the outflow tract, right ventricle, a portion of left ventricular cells, and a significant number of atrial cells. Its activity is vital for these progenitors to contribute to the heart. ISL1 regulates the expression of FGF and BMP growth factors in this cell population, promoting cell proliferation, survival within the pharyngeal foregut endoderm and adjacent splanchnic mesoderm, and the migration of cardiac progenitors into the heart.
ISL1 is also known as ISLET1, Isl-1.
