New details of an unusual biological mechanism in the brains of diverse species that not only helps regulate how their brains develop, but also how they function later in life, have been uncovered by researchers at the University of California, San Diego School of Medicine.
Messenger ribonucleic acid (mRNA) is one of a family of molecules that help transcribe genetic information (DNA) into the construction of proteins essential to life. Nonsense-mediated mRNA decay or NMD is a sort of quality control mechanism used by cells to eliminate errant mRNAs that prematurely terminate these translations.
It's vital to the normal development of the brain and nervous system. When NMD doesn't work correctly, the result in humans can be a range of neurological conditions from mental retardation to attention-deficit disorder, schizophrenia and autism.
Given the over-arching necessity of NMD (the mechanism is found in all eukaryotic life forms, from yeast to humans) and its role in the healthy development and functioning of neural systems, Miles F. Wilkinson and colleagues sought to determine if NMD itself was regulated.
They discovered that a neural circuit involving a microRNA represses NMD activity during embryonic brain development in species as diverse as frogs, chickens and mammals. MicroRNAs are molecules that regulate mRNAs post-translation, typically repressing or turning off genes.
Wilkinson said the research alters what's known about how new proteins are made at specific developmental stages of life.
The study was published recently in the journal Molecular Cell.