Gene expression is the process by which genetic information is used to produce proteins, which are essential for cells to function properly and fulfil their many purposes. It takes place in two distinctive steps: first the transcription, which takes place in the nucleus, then the translation, in the cytoplasm. Control of gene expression is vital for cells to produce the exact proteins that are needed at the right moment. Until now, gene transcription and translation into proteins were thought to be two independent processes. Today, microbiologists at the University of Geneva (UNIGE), Switzerland, and at the European Molecular Biology Laboratory in Heidelberg (Germany) provide additional evidence that these two processes are intrinsically related and show that a protein complex called Ccr4-Not plays a key role in gene expression by acting as a messenger between the nucleus and the cytoplasm. Published in Cell Reports, these results shed light on the very mechanisms governing gene expression, a process that controls the life and death of our cells.

Gene expression refers to the biochemical processes through which the information that is stored in our genes is read like an instruction book to produce proteins that will make our cells function properly. Until now, gene expression was thought to take place in two distinctive steps: first transcription, which takes place in the nucleus, then translation, in the cytoplasm. Today, research led by UNIGE and the European Molecular Biology Laboratory shows that transcription and translation are intrinsically related and continuously influence one another. To do so, a very efficient communication within the cell, between the nucleus and the cytoplasm, is essential. This dialogue is made possible by a protein complex called Ccr4-Not, which globally determines the cell translational capacity.

Gene expression: a two-way street

Martine Collart and her team from the UNIGE Faculty of Medicine discovered in 2014 that the Ccr4-Not complex enables the cytoplasm to provide information to the nucleus during translation. Today, they prove that it is a two way-street communication as the nucleus also communicates information to the cytoplasm at all stages of gene expression, thanks to Ccr4-Not. This complex acts as a messenger between the nucleus and the cytoplasm to ensure that both transcription and translation levels are well adapted. It is also able to enhance translation to compensate for transcriptional stress, thus ensuring that gene expression remains well-balanced.

Organoids grown from genetically edited stem cells are giving scientists a new tool to screen drugs and test treatments.

New cure for SMA?!

Spinal muscular atrophy (SMA) is a disease that causes progressive degeneration in the nerve cells that control muscles, thereby causing muscle weakness and eventually death. SMA affects approximately 200,000 people in the U.S., often children. Now, researchers at the University of Missouri are studying a subtype of SMA, spinal muscular atrophy with respiratory distress type 1 (SMARD1), and have developed a gene replacement therapy that can be used to treat and control the disease in the future.

SMARD1 is a rare genetic condition with high mortality rate that develops primarily between the ages of six weeks and six months. The condition targets the spinal cord and leads to atrophy of body muscles and paralysis of the diaphragm, which is responsible for breathing. As the disease progresses, children with a SMARD1 diagnosis become paralyzed and require continuous artificial ventilation. The average life expectancy of a child diagnosed with SMARD1 is 13 months. Currently, there is no cure or effective treatment for this disease.

“Monogenic diseases like SMARD1, a disease that is caused by one gene, are ideal for gene therapy since the goal of the therapy is to replace the missing or defective gene,” said Chris Lorson, an investigator in the Bond Life Sciences Center and a professor of veterinary pathobiology. “Our goals for this study were to develop a vector that would improve the outcomes of the disease and for the vector to be effective in a single dose.”

The strength of genome-wide association studies (GWAS) lies in their ability to identify new disease biomarkers through large-scale genomic comparisons of afflicted individuals and unaffected controls. Now, using this powerful technique, an international collaboration of researchers has identified five new gene regions that increase a woman’s risk of developing endometrial cancer—one of the most common cancers to affect women—taking the number of known gene regions associated with the disease to nine.

Endometrial cancer affects the lining of the uterus, typically presenting as an adenocarcinoma. Endometrial cancer is the sixth most common cancer in women worldwide and is the most common cancer of the female reproductive tract in developed countries, with over 320,000 new cases diagnosed in 2012.

Investigators at the University of Cambridge, Oxford University, and QIMR Berghofer Medical Research Institute in Brisbane studied the DNA of over 7000 women with endometrial cancer and 37,000 women without cancer to identify genetic variants that affected a woman’s risk of developing the disease.