Systemic antibody light chains (AL) amyloidosis is characterized by deposition of amyloid fibrils derived from a particular antibody light chain. Cardiac involvement is a major risk factor for mortality. Using MAS solid-state NMR, we studied the fibril structure of a recombinant light chain fragment corresponding to the fibril protein from patient FOR005, together with fibrils formed by protein sequence variants that are derived from the closest germline (GL) sequence. Both analyzed fibril structures were seeded with ex-vivo amyloid fibrils purified from the explanted heart of this patient. We find that residues 11-42 and 69-102 adopt β-sheet conformation in patient protein fibrils. We identify arginine-49 as a key residue that forms a salt bridge to aspartate-25 in the patient protein fibril structure. In the germline sequence, this residue is replaced by a glycine. Fibrils from the GL protein and from the patient protein harboring the single point mutation R49G can be both heterologously seeded using patient ex-vivo fibrils. Seeded R49G fibrils show an increased heterogeneity in the C-terminal residues 80-102, which is reflected by the disappearance of all resonances of these residues. By contrast, residues 11-42 and 69-77, which are visible in the MAS solid-state NMR spectra, show 13Cα chemical shifts that are highly like patient fibrils. The mutation R49G thus induces a conformational heterogeneity at the C terminus in the fibril state, whereas the overall fibril topology is retained. These findings imply that patient mutations in FOR005 can stabilize the fibril structure.

Madison T Wright
Nov 18, 2020; 0:RA120.002168v1-mcp.RA120.002168
Research

When the drug Taxol® was approved by the United States Food and Drug Administration in 1993, it was a game changer for cancer patients. The compound, which arrests cell division by preventing the disassembly of tubulin microfibers, has been used over the past three decades to treat millions of cases of breast, lung, and ovarian cancer as well as Kaposi's sarcoma. In 1990, Bristol Myers Squibb applied to trademark the name Taxol, which was approved in 1992, changing the drug's generic name to paclitaxel.At the time that Taxol was entering clinical trials in the late 1970s, it also proved to be a valuable tool for cytoskeletal research. Tubulin had been discovered in the late 1960s, but it was still unclear how the soluble protein dimer polymerized (Fig. 1) to form the long, complex structures of the cytoskeleton.jbc;295/41/13994/F1F1F1Figure 1.Strands of tubulin, a protein in the cell's skeleton, photographed using a high-resolution microscopy technique. Image made by Pakorn Kanchanawong (National University of Singapore) and Clare Waterman (NHLBI, National Institutes of Health).“Back then, people were just discovering the most basic functions of tubulin and how it polymerized, and then they found a drug that affected this,” said Velia Fowler, a cell biologist at the University of Delaware and former Associate Editor at the Journal of Biological Chemistry.The drug and its cytoskeletal activity intersected in the 1981 JBC paper “Taxol-induced polymerization of purified tubulin” (1), the subject of this JBC Classic. In the single-author paper, Nirbhay Kumar, then a postdoctoral fellow at the National...

Priyanka Tripathi
Dec 30, 2020; 0:jlr.RA120001190v1-jlr.RA120001190
Research Articles

An error might occur when you use the SAS 9 BULKLOAD= and BULKEXTRACT= options load data to or extract data from HP Neoview on the HP Itanium platform. The problem occurs because Hewlett-Packard changed the name of one of

Microtubules are polymers composed of αβ-tubulin subunits that provide structure to cells and play a crucial role in in the development and function of neuronal processes and cilia, microtubule-driven extensions of the plasma membrane that have sensory (primary cilia) or motor (motile cilia) functions. To stabilize microtubules in neuronal processes and cilia, α tubulin is modified by the posttranslational addition of an acetyl group, or acetylation. We discovered that acetylated tubulin in microtubules interacts with the membrane sphingolipid, ceramide. However, the molecular mechanism and function of this interaction are not understood. Here, we show that in human iPS cell-derived neurons, ceramide stabilizes microtubules, which indicates a similar function in cilia. Using proximity ligation assays, we detected complex formation of ceramide with acetylated tubulin in C. reinhardtii flagella and cilia of human embryonic kidney (HEK293T) cells, primary cultured mouse astrocytes, and ependymal cells. Using incorporation of palmitic azide and click chemistry-mediated addition of fluorophores, we show that a portion of acetylated tubulin is S-palmitoylated. S-palmitoylated acetylated tubulin is colocalized with ceramide-rich platforms (CRPs) in the ciliary membrane, and it is coimmunoprecipitated with Arl13b, a GTPase that mediates transport of proteins into cilia. Inhibition of S-palmitoylation with 2-bromo palmitic acid or inhibition of ceramide biosynthesis with fumonisin B1 reduces formation of the Arl13b-acetylated tubulin complex and its transport into cilia, concurrent with impairment of ciliogenesis. Together, these data show, for the first time, that CRPs mediate membrane anchoring and interaction of S-palmitoylated proteins that are critical for cilium formation, stabilization, and function. 

Thyroglobulin (Tg) is a secreted iodoglycoprotein serving as the precursor for T3 and T4 hormones. Many characterized Tg gene mutations produce secretion-defective variants resulting in congenital hypothyroidism (CH). Tg processing and secretion is controlled by extensive interactions with chaperone, trafficking, and degradation factors comprising the secretory proteostasis network. While dependencies on individual proteostasis network components are known, the integration of proteostasis pathways mediating Tg protein quality control and the molecular basis of mutant Tg misprocessing remain poorly understood. We employ a multiplexed quantitative affinity purification–mass spectrometry approach to define the Tg proteostasis interactome and changes between WT and several CH-variants. Mutant Tg processing is associated with common imbalances in proteostasis engagement including increased chaperoning, oxidative folding, and engagement by targeting factors for ER-associated degradation (ERAD). Furthermore, we reveal mutation-specific changes in engagement with N-glycosylation components, suggesting distinct requirements for one Tg variant on dual engagement of both oligosaccharyltransferase complex isoforms for degradation. Modulating dysregulated proteostasis components and pathways may serve as a therapeutic strategy to restore Tg secretion and thyroid hormone biosynthesis.

Jerad Eickhoff took his latest first step on Sunday morning at Spectrum Field. He threw a bullpen session, his first since sustaining a setback last month following carpal tunnel surgery in October.

Leading up to the start of Spring Training, the Around the Horn series will examine each of the Angels' positional groupings heading into the 2019 season. Here's a look at the bullpen.

A flight of Florida-based Spirit Airlines was hit by gunfire while attempting to land in Haiti with a crew member that sustained "minor injuries."

Not having to negotiate with federal officials on the finer points of teacher evaluation, rigorous standards, or school turnarounds has made it easier to chart their own paths, some education leaders say.

Looking for new ways to combat kids who bully, some communities are threatening to fine parents with no evidence that the approach is effective.

Where did Georgia land in the latest CFP bracket and rankings? Here’s the College Football Playoff picture for the Bulldogs and path to championship.

Georgia football tumbled nine spots in the College Football Playoff rankings Tuesday and fell out of the 12-team bracket. What committee chair said

Nov. 12—The Gonzaga women's basketball team has much to learn after a challenging loss at Stanford on Sunday. Losses have a way of exposing a team's shortcomings. And there is much to learn from the worst loss (89-58) in coach Lisa Fortier's 11 seasons. Stanford, unranked in the preseason poll for the first time since 1999-2000, is unranked no more. The Cardinal (3-0) entered at No. 24 in the ...

Vertebrate nervous systems use the axon initial segment (AIS) to initiate action potentials and maintain neuronal polarity. The microtubule-associated protein tripartite motif containing 46 (TRIM46) was reported to regulate axon specification, AIS assembly, and neuronal polarity through the bundling, or fasciculation, of microtubules in the proximal axon. However, these claims are based on TRIM46 knockdown in cultured neurons. To investigate TRIM46 function in vivo, we examined male and female TRIM46 knock-out mice. Contrary to previous reports, we find that TRIM46 is dispensable for axon specification and AIS formation. TRIM46 knock-out mice are viable, have normal behavior, and have normal brain structure. Thus, TRIM46 is not required for AIS formation, axon specification, or nervous system function. However, we confirm that TRIM46 is required for microtubule fasciculation. We also show TRIM46 enrichment in the first ~100 μm of axon occurs independently of ankyrinG (AnkG) in vivo, although AnkG is required to restrict TRIM46 only to the AIS. Our results highlight the need for further investigation of the mechanisms by which the AIS and microtubules interact to shape neuronal structure and function.

A new exhibition co-presented by the National Portrait Gallery and the Archives of American Art explores the seminal artist’s work

Human-powered vehicle, to be pedaled by Ironman triathlete, was tested in COSMOSFloWorks' 'virtual wind tunnel'

An overview of the biggest business developments in SA and beyond.

A group of Bulgarian teenagers and leaders took part in this year’s TeenStreet Europe for the first time and experienced God in new ways.

This year at the sports and English camp in Bulgaria, the team noticed the fruit of building on relationships over time.

After making strong observations on the practice of demolishing houses of criminals to send out a strong message against crime, which has come to be known as 'bulldozer justice', the Supreme Court is expected to issue a set of pan-India guidelines fo

Hearing a petition against 'bulldozer justice' today, the Supreme Court today said that the Executive cannot replace the Judiciary and the law should not prejudge an accused's guilt.

After making strong observations on the practice of demolishing houses of criminals to send out a strong message against crime, which has come to be known as 'bulldozer justice', the Supreme Court is expected to issue a set of pan-India guidelines fo

The Executive cannot replace the Judiciary and legal process should not prejudge the guilt of an accused, the Supreme Court said today, taking a tough stand on the issue of 'bulldozer justice'.

Hearing a petition against 'bulldozer justice' today, the Supreme Court today said that the Executive cannot replace the Judiciary and the law should not prejudge an accused's guilt.

The Executive cannot replace the Judiciary and legal process should not prejudge the guilt of an accused, the Supreme Court said today, taking a tough stand on the issue of 'bulldozer justice'.

The overall crypto market cap tumbled by 4.12 percent over the last day due to market fluctuations. Bitcoin and Ether both registered losses on Wednesday. Tether, Solana, and Tron also saw registered losses alongside BTC and ETH. Ripple and Tron saw losses. 

Shalini Passi became an overnight sensation after featuring in the Netflix reality show Fabulous Lives vs Bollywood Wives

As we approach November 14th, we join with our Indian neighbors and friends in celebrating Diwali.  It is the celebration of lights with deep cultural significance, celebrating the victory of light over darkness, good over evil, and knowledge over ignorance.  “I especially wish a Happy Diwali to our sister state of Gujarat,” says Secretary Jeff […]

DOVER, Del.— Delaware Secretary of State Jeff Bullock on Wednesday announced the retirement of Paul Weagraff, Director of the Division of Arts, following 24 of years of service to the Department of State. Weagraff will serve through the end of July.  “Paul and I have served together through the bookends of two great challenges to our arts community: […]

October is National Italian American Heritage Month, a month dedicated to celebrating the distinguished cultural contributions of Americans with Italian lineage. According to the United States Census Bureau, as of 2019, more than 16 million Americans of Italian descent reside in the United States, making up the seventh largest ethnic group in the country. “Italian […]

This year between November 2nd through 6th, the Delaware Department of State joins Indian Delawareans in celebrating Diwali, the annual festival of lights celebrated by Hindus, Jains, and Sikhs. Diwali, which is celebrated over the course of five days, symbolizes the spiritual “victory of light over darkness, good over evil, and knowledge over ignorance.” “As […]

Dover, Del.—Secretary of State Jeff Bullock announced on Friday that Jordan Schulties, Director of the Division of Small Business, and Tim Slavin, Director of the Division of Historical and Cultural Affairs, will depart from their roles to embark on new journeys at the Delaware Department of Technology and Information (DTI) and Fort Dupont Redevelopment & […]

Delaware Secretary of State Jeff Bullock issued a statement following Senator Tom Carper’s decision to not seek reelection in 2024: Tom Carper has literally bent the arch of Delaware history. Everywhere you look up and down our state, Tom Carper has had an impact. His body of work is unprecedented, and it continues to grow, […]

Attorney General Jennings announced Tuesday that the Delaware Department of Justice’s Investor Protection Unit is participating in a consolidated nationwide enforcement action to disrupt a fraudulent precious metals scheme that has solicited more than $180 million from seniors and other investors. The Delaware Department of Justice, the U.S. Commodity Futures Trading Commission, and 29 other […]

Navarro notes consumer reports spurred investigation Following a nearly years-long Market Conduct investigation, Insurance Commissioner Trinidad Navarro announced today penalties against Highmark totaling $363,570 relating to improper volunteer ambulance company claims reimbursement. Investigations began after reports were received that payments were going to residents rather than directly to volunteer ambulance companies for payment of services. […]

1. BREAKING| 'Bulldozer Reminds Of Lawlessness' : Supreme Court Says Properties Can't Be Demolished Merely...  Live Law - Indian Legal News
2. "Officials To Pay From Salary": Top Court Guidelines On 'Bulldozer Justice'  NDTV
3. ‘Heavens won’t fall on authorities if they hold their hands for some period’: SC sets pan India guidelines against bulldozer action  The Financial Express
4. Executive Can't Become Judge, Pronounce Guilt Of Persons & Punish Them By Demolishing Their Properties :...  Live Law - Indian Legal News
5. ‘Officials will pay for demolitions from their salary’: 5 Key SC observations on ‘chilling’ side of ‘bulldozer justice’  Mint

The Enugu State Government has strongly condemned the bullying and physical assault of a student at the Federal Government College, Enugu, describing it as “deeply troubling and emotionally distressing.” The state Commissioner for Education, Prof Ndubueze Mbah, in a statement on Tuesday, emphasised the government’s zero-tolerance policy for bullying, abuse, and dehumanising treatment in all