Tag: Protein Function

Images of yeast containing prion-like proteins and controls

Revising the meaning of “prion”

October 6, 2016

Prions are infamous for causing Creutzfeld-Jakob disease, fatal familial insomnia, and bovine spongiform encephalopathy, commonly known as mad cow’s disease. Yet, it’s not likely that’s all they’re good for. Using an unbiased screen in yeast, a team of Whitehead Institute and Stanford University scientists have identified dozens of prion-like proteins that could change the defining characteristics of these unusual proteins. 

Images of toxoplasma parasites inside of a host cell

Genome-wide Toxoplasma screen reveals mechanisms of parasitic infections

September 1, 2016

Whitehead Institute researchers have conducted the first genome-wide screen in Apicomplexa, a phylum of single-celled parasites that cause diseases such as malaria and toxoplasmosis. The screen sheds light into the vast, unstudied reaches of parasite genomes, uncovering for instance a protein common to all apicomplexans.

Microscope images of mitochondria

Novel method enables absolute quantification of mitochondrial metabolites

August 31, 2016

Whitehead Institute scientists have developed a method to quickly isolate mitochondria from mammalian cells and systematically measure the concentrations of mitochondrial metabolites. Mitochondrial dysfunction is found in several disorders, including Parkinson’s disease, cardiovascular disease, and mitochondrial diseases. Until now, peering into the inner metabolic workings of these vital organelles has been very challenging.

Three images of human lung cells were infected with influenza A virus.

Tiny alpaca-derived antibodies point to targets preventing viral infection

June 20, 2016

Using tiny, alpaca-derived, single-domain antibody fragments, Whitehead Institute scientists have developed a method to perturb cellular processes in mammalian cells, allowing them to tease apart the roles that individual proteins play in these pathways. With improved knowledge of protein activity, scientists can better understand not only basic biology but also how disease corrupts cellular function and identify potential therapeutics to rectify these aberrations.

Photo of plate showing different strengths of prion activity in yeast

Prion-like protein found in plants

April 29, 2016

Whitehead Institute scientists have determined that a plant protein involved in the timing of flowering could in fact be a prion. This is the first time that a possible prion has been identified in plants, and it may play a role in a plant’s “memory” of cold exposure during winter.

Cartoon of CASTOR1's role in mTORC1 regulation

Scientists identify sensor that modulates key metabolic pathway

March 10, 2016

Whitehead Institute researchers have elucidated how the growth-regulating metabolic pathway known as mTORC1 (for mechanistic target of rapamycin complex 1) senses the amino acid arginine. This nutrient sensor may represent a novel therapeutic target for controlling mTORC1, whose activity is often dysregulated in a variety of diseases, including diabetes and cancer. 

Diagram showing the frequency of mutations in the gene for RagC

Scientists identify mTOR pathway mutations in follicular lymphoma

December 21, 2015

A team of researchers from Whitehead Institute and Queen Mary University of London (QMUL) have identified in follicular lymphoma tumors a mutated protein that could serve as a biomarker to predict therapeutic response.

Schematic of looping chromosomal structure

3D map of human genome reveals relationship between mutations and disease development

December 10, 2015

Whitehead Institute researchers have created a map of the DNA loops that comprise the three dimensional (3D) structure of the human genome and contribute to gene regulation in human embryonic stem cells. The location of genes and regulatory elements within this chromosomal framework will help scientists better navigate their genomic research, establishing relationships between mutations and disease development.

Model for the architecture of the CCAN

Architecture of protein complex hints at its foundational function in chromosome segregation

November 19, 2015

The Constitutive Centromere-Associated Network (CCAN) plays a foundational role in the machine that directs chromosome segregation during cell division. On the left is a model of the complete machine (the kinetochore) attached to the microtubule that provides the power for chromosome segregation. The right side depicts the direct interactions between CCAN sub-complexes based on Whitehead scientists’ research as viewed from above the CENP-A nucleosome, either occuring on a single nucleosome (top) or or between two nucleosomes (bottom).”

Schematic showing how amino acid inputs control the activity of the growth-regulating mTORC1 pathway

Scientists discover essential amino acid sensor in key growth-regulating metabolic pathway

October 8, 2015

Whitehead Institute scientists have at last answered the long-standing question of how the growth-regulating pathway known as mechanistic target of rapamycin complex 1 (mTORC1) detects the presence of the amino acid leucine—itself a key player in modulating muscle growth, appetite, and insulin secretion.

Diagram of antiparallel beta-sheet structure of the enzyme catalase

Enhanced-sensitivity NMR could reveal clues on how proteins fold

October 8, 2015

Until now, it has been difficult to fully characterize the different structures that proteins can take on in their natural environments. However, using a new technique known as sensitivity-enhanced nuclear magnetic resonance (NMR), Whitehead Institute and MIT researchers have shown that they can analyze the structure that a yeast protein forms as it interacts with other proteins in a cell.

Microscope image of a B lymphocyte showing the location of the mitochondria in relation to the nucleus and plasma membrane

Hydrogen peroxide induces signals that link the mitochondrial respiratory chain to specific cellular pathway

October 5, 2015

Countering the prevailing theory that cellular hydrogen peroxide signaling is broad and non-specific, Whitehead Institute scientists have discovered that this reactive oxygen species (ROS) in fact triggers a distinct signal transduction cascade under control of the mitochondrial respiratory chain—the Syk pathway—that regulates transcription, translation, metabolism, and the cell cycle in diverse cell types. Hydrogen peroxide and other ROS mediate cellular responses in aging and myriad common chronic diseases, including diabetes, heart disease, stroke, cancer, and neurodegeneration. Understanding how these signals function may point to new therapy targets for these conditions.


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