Length Matters in Gene Expression
News Oct 08, 2012
The findings also explain how some short genes have adapted to circumvent this handicap.
Gene ends communicate
Human genomes harbour thousands of genes, each of which gives rise to proteins when it is active. But which inherent features of a gene determine its activity? Postdoctoral Scholar Pia Kjølhede Andersen and Senior Researcher Søren Lykke-Andersen from the Danish National Research Foundation’s Centre for mRNP Biogenesis and Metabolism have now found that the distance between the gene start, termed the ‘promoter’, and the gene end, the ‘terminator’, is crucial for the activity of a protein-coding gene. If the distance is too short, the gene is transcriptionally repressed and the output is therefore severely decreased. This finding outlines a completely new functional interplay between gene ends.
Small genes utilise specialised terminators
Fortunately, most human protein-coding genes are long and are therefore not repressed by this mechanism. However, some genes, e.g. ‘replication-dependent histone genes’, are very short. How do such genes express their information at all? Interestingly, many of these differ from the longer protein-coding genes by containing specialised terminators. And in fact, if such a specialised terminator replaces a normal terminator in a short gene context, the short gene is no longer transcriptionally repressed. It therefore appears that naturally occurring short genes have evolved ‘their own’ terminators to achieve high expression levels.
The new findings add to a complex molecular network of intragenic communication and help us to understand the basic function of genes.
The researchers behind the results that have just been published in the international journal Genes & Development are affiliated with the Danish National Research Foundation’s Centre for mRNP Biogenesis and Metabolism at the Department of Molecular Biology and Genetics, Aarhus University.
In a new study in cells, University of Illinois researchers have adapted CRISPR gene-editing technology to cause the cell’s internal machinery to skip over a small portion of a gene when transcribing it into a template for protein building. This gives researchers a way not only to eliminate a mutated gene sequence, but to influence how the gene is expressed and regulated.
Researchers published today a detailed description of the complete genome of bread wheat, the world's most widely-cultivated crop. This work will pave the way for the production of wheat varieties better adapted to climate challenges, with higher yields, enhanced nutritional quality and improved sustainability.