Ubiquitin in Biological News

Muscle atrophy through thick but not thin

... not known. MuRF1, an atrophy-related gene, is a ubiquitin ligase that "ubiquitylates," or tags a protein, by attaching a ubiquitin molecule, marking it for degradation by the cell. ... components, whereas others fall victim to other ubiquitin ligases and autophagy. Inhibitors that work ...

A paradigm shift in immune response regulation

... Their results show that interaction with a linear ubiquitin chain is crucial for nuclear factor kappa B ... or the conjugation of small modifier ubiquitin (ubiquitination) - play a central role in ... collaboration to investigate the role of ubiquitin modification in these pathways. The ...

CSHL scientists discover new way in which ubiquitin modifies transcriptional machinery

... the addition of small protein molecules called ubiquitin to other, larger proteins. When ubiquitin "tags" are added to these larger molecules, it ... and colleagues to more comprehensively grasp how ubiquitin functions. They have discovered that Asr1 ...

St. Jude study gives new insights into how cells accessorize their proteins

... given environment. One of the major functions of ubiquitin is to mark a protein for disposal when its job is ... to cullin-RING, it activates the enzyme to attach ubiquitin to its target protein. In this activation process ... CAND1, activating cullin-RING to then put ubiquitin onto a different target protein. The open state ...

Glue inside the cell

... which constitute a subgroup of lymphocytes, ubiquitin is attached to the Malt1 protein in response to ... of T cell activation. Mechanistically, ubiquitin is virtually acting as all-purpose glue that ... to demonstrate the potential of targeting the ubiquitin system for the development of novel therapeutic ...

A study by the MUHC and McGill University opens a new door to understanding cancer

... In a cells interior, the function of the ubiquitin molecule is to clean house. It attaches itself to ... minutely controlled. This new study reveals that ubiquitin also promotes interactions between proteins known ... does not appear to function, partly because the ubiquitin does not attach itself correctly to the cell ...

Self-digestion as a means of survival

... which are destined to be discarded are marked with the small protein ubiquitin and this is recognised by a receptor located at the gateway to the ... proteins have a similar chain-like structure. At one end they bind to the ubiquitin that marks the protein aggregates and organelles that are to be degraded. ...

Conaway Lab identifies novel mechanism for regulation of gene expression

... tags (called ubiquitin) from other proteins. The presence of one kind of ubiquitin tag on a protein can mark it for destruction, but others serve as marks to ... to regulate these enzymes is very important because promiscuous removal of ubiquitin marks could lead to a failure to regulate properly the activities or ...

Model for angelman syndrome developed by University of Texas at Austin biologists

... The UBE3A protein is an enzyme that attaches a small protein called ubiquitin to other proteins. ubiquitin attachment signals that the tagged protein needs to be degraded. "The ...

RING finger protein 5 may guide treatment for muscle disease in older adults

... identify and remove those proteins that are not properly folded. ubiquitin ligase RNF5 (or RING Finger Protein 5) acts much like one of these ... he explains, still need to be addressed. We know the substrates for this ubiquitin ligase in C. elegans, but not yet in human muscle. ...

Lipid droplets lead a Spartin existence

... or knocking-down the protein caused an increase in both the organelle's size and number. In turn, Spartin is regulated by ubiquitination by the ubiquitin ligase WWP1. Overexpressed WWP1 removed Spartin from LDs and promoted its degradation. A truncated form of Spartin found in a rare neuronal ...

New research helps explain genetics of Parkinson's disease

... . Both articles will be published online Monday, November 24 ( www.jcb.org ). Loss-of-function mutations in the gene Park2, which encodes an E3 ubiquitin ligase (Parkin), are implicated in half the cases of recessive familial early-onset Parkinson's disease. Several lines of evidence suggest that ...

Death, division or cancer? Newly discovered checkpoint process holds the line in cell division

... Yen. Yen, along with visiting researcher Avram Hershko, Ph.D., of Technion, discovered the ability of MCF2 to block mitosis by shutting down an ubiquitin ligase enzyme known as the anaphase-promoting complex/cyclosome (APC/C). Hershko was awarded the 2004 Nobel Prize for Chemistry along with former Fox ...

MIT finds most complex protein knot ever seen

... knot, was initially found in only one protein - ubiquitin hydrolase. That complex knot may hold some protective value for ubiquitin hydrolase, whose function is to rescue other ... protein in and chops it into pieces. However, if ubiquitin hydrolase intervenes and removes the ubiquitin, ...

Study reveals how cells destroy faulty proteins in cystic fibrosis

... identified by the Cyr group are two different ubiquitin ligases, proteins that specifically recognize ... with a degradation signal known as ubiquitin. The ubiquitin tag tells the cell to destroy the marked CFTR, a ... the proteasome. This trash system is known as the ubiquitin proteasome pathway. "We've identified the ...

Bacterial protein mimics host to cripple defenses

... revealed that the protein looks very much like a ubiquitin ligase, an enzyme plant and animal cells use to attach the small protein ubiquitin to unneeded or defective proteins. Other enzymes ... the protein that correspond to crucial sites on ubiquitin ligase. These changes rendered Pseudomonas ...

MSKCC researchers uncover structure of key protein complex in cells

... though they perform different tasks in cells. ubiquitin acts as a chemical tattoo that marks damaged or ... researchers became particularly interested in ubiquitin with the discovery that it tags and regulates ... can prevent runaway cell growth. In normal cells ubiquitin marks p53 for destruction. But in cells with ...

Enzyme shown to help protect genomic stability

... the addition or removal of acetyl, methyl, and ubiquitin molecules in prescribed sequences and patterns. ... Ubp10, as identified in this study, is to remove ubiquitin from certain histones where ubiquitin is associated with gene activation and to ...

Bound for destruction: Ubiquitination protects against improper Notch signaling

... in which proteins are tagged by a complex of ubiquitin proteins. This system is best known for its ... attention was drawn to Nedd4 (a member of the ubiquitin ligase family of molecules that directly bind to ... by the proteasome, and indeed other types of ubiquitin ligase have been shown to operate in the ...

Proteasome activator enhances survival of Huntington's disease neuronal model cells

... with a central role of clearing such protein build up in the cell is the ubiquitin proteasome system (UPS). In Huntington's disease (HD) brains and other ... to expression of huntingtin protein with longer CAG repeats can reduce the ubiquitin proteasome system (UPS) function in Huntington¡¦s disease cells. Following ...

Weizmann Institute scientists discover a molecular security mechanism for keeping mutations in check

... of DNA. When the enzyme encounters DNA damage, a small molecule called ubiquitin attaches to the clamp. The ubiquitin, in this case, serves to anchor ... The p21 then acts as a sort of facilitator, helping to fasten the proper ubiquitin in place and clearing stalled DNA polymerase out of the way so its ...

Brain enzyme treatment relieves memory lapse in Alzheimer's mice

... Treatments that elevate the protein, known as ubiquitin C-terminal hydrolase L1 (Uch-L1), might therefore ... of Alzheimer's disease, he added. ubiquitin is a "tag" that marks proteins for destruction by ... by the proteasome, Uch-L1 must remove their ubiquitin tag. Earlier studies found that the brains of ...

UT Southwestern researchers discover master switch in cell death

... cell extracts, the researchers found that Mule caused a protein called ubiquitin to bind to several sites on Mcl-1. When ubiquitin binds to a molecule, it serves as a flag for that molecule to be ....

New binding target for oncogenic viral protein

... also binds to another tumor suppressor, Fbw7. This protein is part of a ubiquitin ligase complex that adds ubiquitin to proteins to mark them for destruction by the cell. Fbw7 recognizes a ...

Penn researchers link cell's protein recycling systems

... week in Nature. The cell has two internal pathways for breaking down proteins. The ubiquitin-proteasome pathway marks unwanted proteins with ubiquitin tags and shuttles them for rapid breakdown to a complicated structure called the proteasome. The second is the autophagy-lysosomal system, a more ...

An AIDS-related virus tricks cells to become tumors, new Penn study finds

... for Disposal The trick is played out in a cell process called ubiquitylation. This refers to a pathway in all cells whereby a protein aptly named ubiquitin binds to cellular proteins and marks them for degradation. This process can be likened to putting out the garbage for disposal. Ubiquitylation ...

New mechanism for essential genome-wide gene silencing identified

... team also noted a dynamic interplay between the addition of a SUMO protein to a histone ?sumoylation ?and the addition of either an acetyl group or a ubiquitin protein to a histone. The processes appear to be mutually exclusive. "Acetylation and ubiquitylation have both been shown in earlier studies to ...

How Rickettsial pathogens break into cells

... already shown that Ku70 has to be present in certain well-organized regions of the cell membrane called rafts, and that the protein modifier called ubiquitin modifies Ku70 as soon as the bacteria interact with it. This step is critical for cell entry. "Whether other Rickettsia and other pathogens use Ku70 ...

Telling axons where to go - and grow

... the ubiquitin/proteosome protein degradation pathway in the regulation of local actin dynamics in neurons. The authors are able to show that the ubiquitin ligase Rnf6 polyubiquitinates the kinase LIMK1, targeting it for proteosomal degradation in the growth cones of hippocampal neurons. LIMK1 regulates ...

Mechanism for Epstein-Barr virus protein's role in blood cancers discovered

... infected with the Epstein-Barr virus, the investigators found that EBNA3C recruits a group of molecules called the SCF complex, which attaches ubiquitin to Rb. This inadvertently tags Rb for degradation by the proteosome machinery, the cell's recycling plant. With Rb out of the way, the cell now ...

Insight into natural cholesterol control suggests novel cholesterol-lowering therapy

... to intact cells and cellular components in test tubes, lanosterol led other proteins to mark reductase for destruction by attaching a protein called ubiquitin in a process called ubiquitination. Ubiquitination is a common mechanism for stimulating protein degradation. Cholesterol itself had no such effect ...