Quality control mechanism closes the protein production ‘on-ramps’ in cells

Quality control mechanism closes the protein production 'on-ramps'
An illustration of stalled ribosomes as stalled cars on a freeway. New work shows that factors GIGYF2 and 4EHP prevent translation from being initiated on problematic messenger RNA fragments. This is akin to closing an on-ramp to prevent additional traffic backups after an incident. Credit: Kamena Kostova and Navid Marvi.

Recent work led by Carnegie’s Kamena Kostova revealed a new quality control system in the protein production assembly line with possible implications for understanding neurogenerative disease.


The DNA that comprises the chromosomes housed in each cell’s nucleus encodes the recipes for how to make proteins, which are responsible for the majority of the physiological actions that sustain life. Individual recipes are transcribed using messenger RNA, which carries this piece of code to a piece of cellular machinery called the ribosome. The ribosome translates the message into amino acids—the building blocks of proteins.

But sometimes messages get garbled. The resulting incomplete

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Factors that influence patterns in protein distribution — ScienceDaily

In plants, many proteins are found at only one end of a cell, giving them a polarity like heads and tails on a coin.

Often, cells next to each other have these proteins at the same end, like a stack of coins with heads all facing up. This protein patterning is critical for how plant cells orient and coordinate themselves to produce the leaves, flowers, stems and roots that adorn our gardens and provide us with all our food and the oxygen we breathe.

Previously it’s been unclear how this head-to-tail protein patterning is produced: can it arise within each cell, or does it depend on a collective effort of many cells working together?

A new paper, published in Current Biology has found that even cells in isolation can become polarised to create the head to tail pattern, and that this polarity can orient how the cell grows.

The team,

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IL-21 protein a key part of immune response to central nervous system infections — ScienceDaily

Researchers at Penn State College of Medicine now better understand the role of a protein, interleukin-21 (IL-21), in the immune system response to infections in the nervous system. The results of their recent study support further investigation into using IL-21 as a therapeutic agent for persistent central nervous system infections.

CD4 T cells in the immune system produce IL-21, which is critical for the development of CD8 tissue-resident-memory (TRM) cells during persistent viral infections of the central nervous system with polyomavirus.

Dr. Aron Lukacher, professor and chair of the Department of Microbiology and Immunology, said the results, published in Science Immunology, demonstrate that IL-21 is an important factor in the development of effective immune responses to chronic infections in the central nervous system including neurodegenerative HIV-AIDS and progressive multifocal leukoencephalopathy (PML), a fatal brain infection caused by JC polyomavirus. PML starts with symptoms including clumsiness, weakness or difficulty speaking

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Researchers identify a new source of protein for humans — ScienceDaily

Rapeseed has the potential to replace soy as the best plant-based source of protein for humans. In a current study, nutrition scientists at the Martin Luther University Halle-Wittenberg (MLU), found that rapeseed protein consumption has comparable beneficial effects on human metabolism as soy protein. The glucose metabolism and satiety were even better. Another advantage: The proteins can be obtained from the by-products of rapeseed oil production. The study was published in the journal Nutrients.

For a balanced and healthy diet, humans need protein. “It contains essential amino acids which can not be synthesized in the body,” says Professor Gabriele Stangl from the Institute of Agricultural and Nutritional Sciences at MLU. Meat and fish are important sources of high-quality proteins. However, certain plants can also provide valuable proteins. “Soy is generally considered the best source of plant protein as it contains a particularly beneficial composition of amino acids,” says Stangl.

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Levels of protein called suPAR linked to acute kidney injury in patients studied — ScienceDaily

Hospitalized patients with COVID-19 may face an increased risk for kidney injury, a dreaded complication for those suffering from infection with the novel 2019 coronavirus, an observational study led by University of Michigan researchers has found.

According to Jochen Reiser, MD, PhD, the Ralph C Brown MD professor and chairperson of Rush’s Department of Internal Medicine, patients with COVID-19 experience elevated levels of soluble urokinase receptor (suPAR), an immune-derived pathogenic protein that is strongly predictive of kidney injury.

“SuPAR is a circulating factor we’ve seen contribute to kidney injury in thousands of patients,” Reiser said. “RNA viruses such as HIV and SARS-CoV-2 (the virus that causes COVID-19) elicit a suPAR response of the innate immune system, leading to a rise in blood suPAR levels. If there is a hyperinflammatory suPAR response, kidney cells may be damaged.”

Reiser is an author of the multicenter study led by Salim Hayek MD, an

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Glycans in the SARS-CoV-2 spike protein play active role in infection

Glycans in the SARS-CoV-2 spike protein play active role in infection
In this illustration, glycans (dark blue) coat the SARS-CoV-2 spike protein (light blue), which is anchored in the viral envelope (colorful bilayer on bottom). Credit: Adapted from ACS Central Science 2020, DOI: 10.1021/acscentsci.0c01056

As the COVID-19 pandemic rages on, researchers are working overtime to develop vaccines and therapies to thwart SARS-CoV-2, the virus responsible for the disease Many efforts focus on the coronavirus spike protein, which binds the angiotensin-converting enzyme 2 (ACE2) on human cells to allow viral entry. Now, researchers reporting in ACS Central Science have uncovered an active role for glycans—sugar molecules that can decorate proteins—in this process, suggesting targets for vaccines and therapies.


Before the SARS-CoV-2 spike protein can interact with ACE2 on a human cell, it changes shape to expose its receptor binding domain (RBD), the part of the protein that interacts with ACE2. Like many viral proteins, the SARS-CoV-2 spike protein has a thick coat

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