Protein subcellular localization is an essential and highly regulated determinant of protein function. Major advances in mass spectrometry and imaging have allowed the development of powerful spatial proteomics approaches for determining protein localization at the whole cell scale. Here, a brief overview of current methods is presented, followed by a detailed discussion of organellar mapping through proteomic profiling. This relatively simple yet flexible approach is rapidly gaining popularity, due to its ability to capture the localizations of thousands of proteins in a single experiment. It can be used to generate high-resolution cell maps, and as a tool for monitoring protein localization dynamics. This review highlights the strengths and limitations of the approach, and provides guidance to designing and interpreting profiling experiments. 

Perlecan is a critical proteoglycan found in the extracellular matrix (ECM) of cartilage. In healthy cartilage, perlecan regulates cartilage biomechanics and we previously demonstrated perlecan deficiency leads to reduced cellular and ECM stiffness in vivo. This change in mechanics may lead to the early onset osteoarthritis seen in disorders resulting from perlecan knockdown such as Schwartz-Jampel syndrome (SJS). To identify how perlecan knockdown affects the material properties of developing cartilage, we used imaging and liquid chromatography–tandem mass spectrometry (LC-MS/MS) to study the ECM in a murine model of SJS, Hspg2C1532Y-Neo. Perlecan knockdown led to defective pericellular matrix formation, whereas the abundance of bulk ECM proteins, including many collagens, increased. Post-translational modifications and ultrastructure of collagens were not significantly different; however, LC-MS/MS analysis showed more protein was secreted by Hspg2C1532Y-Neo cartilage in vitro, suggesting that the incorporation of newly synthesized ECM was impaired. In addition, glycosaminoglycan deposition was atypical, which may explain the previously observed decrease in mechanics. Overall, these findings provide insight into the influence of perlecan on functional cartilage assembly and the progression of osteoarthritis in SJS.

A fundamental feature of the eukaryotic cell membrane is the asymmetric arrangement of lipids in its two leaflets. A cell invests significant energy to maintain this asymmetry and uses it to regulate important biological processes, such as apoptosis and vesiculation. The dynamic coupling of the inner or cytoplasmic and outer or exofacial leaflets is a challenging open question in membrane biology. Here, we combined fluorescence lifetime imaging microscopy (FLIM) with imaging total internal reflection fluorescence correlation spectroscopy (ITIR-FCS) to differentiate the dynamics and organization of the two leaflets of live mammalian cells. We characterized the biophysical properties of fluorescent analogs of phosphatidylcholine, sphingomyelin, and phosphatidylserine in the plasma membrane of two mammalian cell lines (CHO-K1 and RBL-2H3). Because of their specific transverse membrane distribution, these probes allowed leaflet-specific investigation of the plasma membrane. We compared the results of the two methods having different temporal and spatial resolution. Fluorescence lifetimes of fluorescent lipid analogs were in ranges characteristic for the liquid ordered phase in the outer leaflet and for the liquid disordered phase in the inner leaflet. The observation of a more fluid inner leaflet was supported by free diffusion in the inner leaflet, with high average diffusion coefficients. The liquid ordered phase in the outer leaflet was accompanied by slower diffusion and diffusion with intermittent transient trapping. Our results show that the combination of FLIM and ITIR-FCS with specific fluorescent lipid analogs is a powerful tool for investigating lateral and transbilayer characteristics of plasma membrane in live cell lines.

As Emilio Pagan enters his first Spring Training with the Rays, he's looking to prove that he can perform well against hitters on either side of the plate.

VOLUME 295 (2020) PAGES 4079–4092There was an error in the abstract. “The pyridinium cation hampers uptake of OPs into the central nervous system (CNS)” should read as “The pyridinium cation hampers uptake into the central nervous system (CNS).”

The Open Arms Development Centre, a homeless shelter in downtown Kingston, and Jamaica’s COVID-19 Response Fund Food Relief are among 25 charitable and community organisations across the island to benefit from the latest round of grants from US-...

As England’s presumed consent law for 2020 clears parliament, Veronica English, head of medical ethics and human rights at the BMA, say that evidence from Wales and other countries shows that it could increase transplantation rates. But Blair L Sadler, physician and senior adviser to California State University, consider such legal changes a...

Margaret Heffernan has thought a lot about whistleblowing, and why companies don't respond well to it. She wrote the "Book Wilful Blindness: Why We Ignore the Obvious at our Peril". In this podcast she talks about how culture, and groupthink, leads to a culture where whistleblowers are ignored, and why the NHS needs to change the way it treats...

Reports from Italy, and more recently from the U.S. show the strain the healthcare system is under during this pandemic. We know that staff will step up in an emergency, but this isn’t a fire or a bombing, this is going to last for months. So how can organisations be proactive in supporting staff, and how can leaders try to mitigate the...

Norikazu Maeda
Sep 1, 2001; 50:2094-2099
Pathophysiology

In his first public address on his inaugural official visit to Washington, DC, IOM Director General António Vitorino discusses his vision for IOM; reforms in the UN system; coordination with other organizations in addressing humanitarian protection; and the operational steps IOM is taking to respond to forced migration and displacement.

El Salvador is the smallest country in Central America yet the most densely populated. A stagnant economy, high levels of crime and violence, and natural disasters have pushed growing numbers of people to migrate without authorization or seek asylum abroad, mostly in the United States. This article explores historical and contemporary emigration from El Salvador.

In his first public address during his inaugural formal visit to Washington, DC. International Organization for Migration (IOM) Director General António Vitorino discussed his vision for the agency; reforms in the UN system designed to address migration matters better; the coordination of efforts between IOM, the UN High Commissioner for Refugees, and other international partners in addressing humanitarian protection; and the operational steps IOM is taking to respond to forced migration and displacement in hotspots around the world, including Venezuela, Bangladesh, and Libya.

Michigan coach Jim Harbaugh is urging the NFL and NCAA to amend their rules and provide flexibility to college football players who consider making the jump to the next level.

Francesco Rubino
Jun 1, 2016; 39:861-877
Metabolic Surgery and the Changing Landscape for Diabetes Care

Francesco Rubino
Jun 1, 2016; 39:861-877
Metabolic Surgery and the Changing Landscape for Diabetes Care

The Organized Dentistry Coalition is applauding Congress for introducing legislation aimed at improving oral health literacy.

The ADA, along with a large group of other dental organizations, told the U.S. Department of Labor that they are concerned about provisions in HR 6201, the Families First Coronavirus Response Act as related to family and medical leave and paid sick leave.

The ADA and nearly 100 other organizations are asking Congress and the White House to help businesses survive the coronavirus crisis by reducing their costs and increasing their cash flow as much as possible in the coming weeks.

The ADA and other health care organizations signed a public statement March 27 saying they “strongly” support emergency efforts at the federal level to dramatically increase the production and distribution of personal protective equipment (PPE) and other necessary medical equipment and supplies during the COVID-19 pandemic.

Traveling with purpose is what has led Nevada City, California-based general dentist Dr. Jean Creasey to a rural district in the southwestern region of Uganda over the past 15 years as a member of the Kellermann Foundation, treating and helping educate the villagers on the importance of good oral health as a way to a better future.

The ADA, Organized Dentistry Coalition, and many state dental associations are asking the U.S. Department of Health and Human Services and Centers for Medicare & Medicaid Services to release funding from the Coronavirus Aid, Relief and Economic Security Act Provider Relief Fund to assist dental Medicaid providers.

The Organized Dentistry Coalition is asking Congress for flexibility in the Paycheck Protection Program to allow dentists to purchase personal protective equipment as states begin the reopening phase of the COVID-19 pandemic.

OBJECTIVE

To examine the association between manganese intake and the risk of type 2 diabetes in postmenopausal women and determine whether this association is mediated by circulating markers of inflammation.

Authorities have charged a fourth person connected to the shooting death of a Flint, Mich., security guard who was killed after confronting a customer who entered a store without a state-mandated facemask.

Secretary of State Mike Pompeo plans to travel to Israel next week to meet with Prime Minister Benjamin Netanyahu in his first international trip since coronavirus-related restrictions were put in place.

Neurons in the hippocampus categorize what we experience into abstract, discrete events, such as taking a walk versus having lunch

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Days before the Sept. 11, 2001, attacks, Osama bin Laden left his compound in Kandahar in Afghanistan and headed into the mountains. His driver, Salim Ahmed Hamdan, traveled with him. As U.S. and Northern Alliance forces stood poised to capture Kandahar a few months later, bin Laden told Hamdan t...

This recipe features on Foodie Tuesday, a weekly segment on 774 Drive with Raf Epstein, 3.30PM, courtesy of Kathy Tsaples.

An indulgent French chocolate and salted caramel tart. Decorate with fresh raspberries and pistachio nuts for great colour and a sweet zing.

OBJECTIVE

To construct and internally validate prediction models to estimate the risk of long-term end-organ complications and mortality in patients with type 2 diabetes and obesity that can be used to inform treatment decisions for patients and practitioners who are considering metabolic surgery.

Two forthcoming pieces in History of the Human Sciences may be of interest to AHP readers. Full details below. “Cold War Pavlov: Homosexual aversion therapy in the 1960s,” by Kate Davison. Abstract: Homosexual aversion therapy enjoyed two brief but intense periods of clinical experimentation: between 1950 and 1962 in Czechoslovakia, and between 1962 and 1975 … Continue reading Forthcoming in HHS: Homosexual Aversion Therapy, Comte on Organism-Environment Relationships →

The two states are the first in 20 years to add such a requirement.

"Tom's Holiday is all about road safety for young children. Tom and his family park the car and head for the beach at a little beachside village. The beachside village is different from home in the city - there are no footpaths. Mum and Dad teach Tom that we must be careful because holiday towns don't have kerbs and gutters. The roads can be thin and there aren't white lines. It's very important that children hold their parent's hand" -- From the Internet.

Speculative fiction, Australian.

Fake news -- United States -- Juvenile literature.

Fermented foods.

Social psychology -- Australia.

Weinstein, Harvey, 1952-

Lyricists -- Australia -- Biography.

Quin, Tegan, 1980- -- Childhood and youth.

Leipzig : G. Thieme, 1890-1891.