Talking Glossary of Genetic Terms
A histone is a protein that provides structural support to a chromosome. In order for very long DNA molecules to fit into the cell nucleus, they wrap around complexes of histone proteins, giving the chromosome a more compact shape. Some variants of histones are associated with the regulation of gene expression.
Histones are proteins that are critical in the packing of DNA into the cell and into chromatin and chromosomes. They're also very important for regulation of genes. We used to think that histones acted essentially as DNA suitcases to sort of hold the DNA, but it was very clear that histones are regulated and have a lot to do with when genes are turned on and turned off. You can think about them as a regulated suitcase that determines when the suitcase is opened and a gene gets out. So they turn out to have very important functions, not only structurally, but also in the regulation of gene function in expression.
Name: William Gahl, M.D., Ph.D.
Occupation: Clinical Director, NHGRI Medical Genetics Branch; Head, Human Biochemical Genetics Section
Biography: Dr. Gahl studies rare inborn errors of metabolism through the observation and treatment of patients in the clinic, and through biochemical, molecular biological and cell biological investigations in the laboratory. His group focuses on a number of disorders, including cystinosis, Hermansky-Pudlak syndrome, alkaptonuria and sialic acid diseases. Dr. Gahl has a long-standing research interest in cystinosis, a lysosomal storage disorder caused by a mutation in the CTNS gene. Over the past two decades, Dr. Gahl's laboratory has elucidated the pathogenesis of this disease and demonstrated the safety and efficacy of cysteamine (²-mercaptoethylamine) therapy, a treatment that depletes cells of cystine.