Description
Huntington's Disease (HD) and Spinocerebellar ataxia type 3 (SCA3) are fatal inherited neurodegenerative diseases characterized by deteriorating physical and mental abilities, caused by a polyglutamine (polyQ) expansion either in the huntingtin (Htt) gene or the ATXN3 gene. The gene causing Huntington?s Disease and Spinocerebellar ataxia have a region where three of the bases, CAG, is repeated many times. Little is known about which pathways are affected by the Htt and ATXN3 protein expression, so to gain a better understanding about the pathways and regulation involved, the Htt and ATXN3 genes have been studied in the fruitfly Drosophila melanogaster. We have shown that expression of long form HTT and ATXN3 genes disrupt the morphology of neuronal dendrites in various polyglutamine diseases, such as Huntington?s disease and SCA3. The defects observed were found to be caused by the disruption of the F-actin cytoskeleton which could be rescued through Rac signaling. Rac is a GTPase known to regulate actin structure by interacting with Formins, like Form3, which are actin nucleating proteins that help promote the development of linear actin filaments. The Drosophila is an excellent model for studying this pathway as we can target expression of the genes to the photoreceptors, which are not important for fly development in a laboratory setting. Overall, this research is important because we were able to model actin regulation in dendrites in Drosophila photoreceptors as the actin regulation pathway is similar.
Polyglutamine Proteins on Actin Structure in Drosophila Photoreceptors
Huntington's Disease (HD) and Spinocerebellar ataxia type 3 (SCA3) are fatal inherited neurodegenerative diseases characterized by deteriorating physical and mental abilities, caused by a polyglutamine (polyQ) expansion either in the huntingtin (Htt) gene or the ATXN3 gene. The gene causing Huntington?s Disease and Spinocerebellar ataxia have a region where three of the bases, CAG, is repeated many times. Little is known about which pathways are affected by the Htt and ATXN3 protein expression, so to gain a better understanding about the pathways and regulation involved, the Htt and ATXN3 genes have been studied in the fruitfly Drosophila melanogaster. We have shown that expression of long form HTT and ATXN3 genes disrupt the morphology of neuronal dendrites in various polyglutamine diseases, such as Huntington?s disease and SCA3. The defects observed were found to be caused by the disruption of the F-actin cytoskeleton which could be rescued through Rac signaling. Rac is a GTPase known to regulate actin structure by interacting with Formins, like Form3, which are actin nucleating proteins that help promote the development of linear actin filaments. The Drosophila is an excellent model for studying this pathway as we can target expression of the genes to the photoreceptors, which are not important for fly development in a laboratory setting. Overall, this research is important because we were able to model actin regulation in dendrites in Drosophila photoreceptors as the actin regulation pathway is similar.