8 January 2020 , Volume 96, Number 1

Saverio Cinti
Nov 1, 2005; 46:2347-2355
Research Articles

Motor protein-based active transport is essential for mRNA localization and local translation in animal cells, yet how mRNA granules interact with motor proteins remains poorly understood. Using an unbiased yeast two–hybrid screen for interactions between murine RNA-binding proteins (RBPs) and motor proteins, here we identified protein interaction with APP tail-1 (PAT1) as a potential direct adapter between zipcode-binding protein 1 (ZBP1, a β-actin RBP) and the kinesin-I motor complex. The amino acid sequence of mouse PAT1 is similar to that of the kinesin light chain (KLC), and we found that PAT1 binds to KLC directly. Studying PAT1 in mouse primary hippocampal neuronal cultures from both sexes and using structured illumination microscopic imaging of these neurons, we observed that brain-derived neurotrophic factor (BDNF) enhances co-localization of dendritic ZBP1 and PAT1 within granules that also contain kinesin-I. PAT1 is essential for BDNF-stimulated neuronal growth cone development and dendritic protrusion formation, and we noted that ZBP1 and PAT1 co-locate along with β-actin mRNA in actively transported granules in living neurons. Acute disruption of the PAT1–ZBP1 interaction in neurons with PAT1 siRNA or a dominant-negative ZBP1 construct diminished localization of β-actin mRNA but not of Ca2+/calmodulin-dependent protein kinase IIα (CaMKIIα) mRNA in dendrites. The aberrant β-actin mRNA localization resulted in abnormal dendritic protrusions and growth cone dynamics. These results suggest a critical role for PAT1 in BDNF-induced β-actin mRNA transport during postnatal development and reveal a new molecular mechanism for mRNA localization in vertebrates.

8 January 2020 , Volume 96, Number 1

The transcription factor forkhead box P3 (FOXP3) is a biomarker for regulatory T cells and can also be expressed in cancer cells, but its function in cancer appears to be divergent. The role of hepatocyte-expressed FOXP3 in hepatocellular carcinoma (HCC) is unknown. Here, we collected tumor samples and clinical information from 115 HCC patients and used five human cancer cell lines. We examined FOXP3 mRNA sequences for mutations, used a luciferase assay to assess promoter activities of FOXP3's target genes, and employed mouse tumor models to confirm in vitro results. We detected mutations in the FKH domain of FOXP3 mRNAs in 33% of the HCC tumor tissues, but in none of the adjacent nontumor tissues. None of the mutations occurred at high frequency, indicating that they occurred randomly. Notably, the mutations were not detected in the corresponding regions of FOXP3 genomic DNA, and many of them resulted in amino acid substitutions in the FKH region, altering FOXP3's subcellular localization. FOXP3 delocalization from the nucleus to the cytoplasm caused loss of transcriptional regulation of its target genes, inactivated its tumor-inhibitory capability, and changed cellular responses to histone deacetylase (HDAC) inhibitors. More complex FKH mutations appeared to be associated with worse prognosis in HCC patients. We conclude that mutations in the FKH domain of FOXP3 mRNA frequently occur in HCC and that these mutations are caused by errors in transcription and are not derived from genomic DNA mutations. Our results suggest that transcriptional mutagenesis of FOXP3 plays a role in HCC.

As businesses slowly reopen, experts warn that social distancing may need to be dialed back up: ‘It’s not an on-off switch’ * Coronavirus – latest US updates * Coronavirus – latest global updatesSome California businesses on Friday began opening their doors for business – at least partially.As states and counties across the nation contend with pressure to lift the stay-at-home measures that have destroyed local economies, California is taking an especially cautious approach, walking a fine line between political and economic pressure to reopen and the public health imperative to stop the spread of disease.Public health experts told the Guardian that while no US state was equipped with enough coronavirus testing and surveillance to feel fully confident reopening, California’s slow, piecemeal recovery plan – though far from perfect – seemed like the least risky option. The planSeven weeks after the governor, Gavin Newsom, ordered his 40 million constituents to shelter in place and all non-essential businesses to close, California on Friday entered phase two of its grand reopening plan.Some retail stores, including bookshops, florists, music stores, clothing and sporting goods retailers, can reopen if they organize curbside pickup. Some manufacturing and logistics in the retail supply chain can restart as well, as long as they follow safety and hygiene protocols. And local authorities are allowed to ease regulations further than the state guidelines if they meet certain testing and sanitation requirements.Phase three of the plan – potentially months away – could see salons, gyms, movie theaters and in-person church services resume. Phase four would end all restrictions. The timingFriday’s reopenings come as California has avoided the surge of infections states like New York have seen. And although California has seen more than 61,000 cases and 2,500 deaths, its hospitals have not been overwhelmed.Last week, state officials reported the first week-over-week decline in Covid-19 deaths.The new guidelines also follow small but sustained protests across the state to demand a relaxation of regulations to revive the state’s crippled economy, and some rural counties have partially reopened in defiance of the lockdown measures. The caveatsHowever, California still hasn’t seen the two weeks of declining cases that the White House suggested as a criterion for easing restrictions and that several European countries have used as a benchmark.The state also lacks the robust testing and tracking systems that countries such as Germany and South Korea have used.The state has ramped up its ability to administer and process tests, although for now, its rate of 29,414 tests a day is below the figure required by some analyses.Authorities are working to put a robust contact tracing effort in place to make sure those who test positive get the care they need and are able to isolate themselves until they recover. Although some counties and communities have spearheaded community-wide testing and tracing programs, overall, the state isn’t at the point where its system is as widespread or efficient as a country like Germany’s.Experts say California should also have a system in place to make sure vulnerable, unhoused populations have access to shelter and medical care – to prevent infection flare-ups in homeless shelters and encampments. Progress on those measures heavily varies county by county.And ideally, there would be a treatment or a vaccine before reopening, said Dr Richard Jackson, a professor emeritus at the UCLA Fielding School of Public Health and the former head of the California department of public health. While we await a cure, Jackson cautioned, “no one should feel completely safe as we remove restrictions.” The trade-offsCalifornia’s reopening strategy stands in sharp contrast to the approach of states like Georgia, which suddenly allowed gyms, barber shops, hair salons, tattoo parlors and bowling alleys to welcome customers last week.“What certain places have done, where they’ve just thrown open the doors and said, ‘OK, we don’t have to keep our distance any more,’ is a colossal mistake,” Jackson said. Reopening businesses that put lots of people into close contact and speed the spread of disease will reverse the success of shelter-in-place rules, he noted, and overwhelm hospitals as cases surge. “Doing it very cautiously and carefully does make sense at this point in time,” he said.“I get that governors have to balance the public health goals with the economic goals,” said Dr Robert Tsai, surgeon and health policy researcher at Brigham and Women’s hospital in Boston and the Harvard TH Chan School of Public Health. “But this stage of the pandemic is really all about trade-offs,” he noted. The weeks aheadIn the coming weeks, state and local leaders will have to watch closely and prepare to dial the distancing back up if the number of cases surges, said Tsai.“Social distancing isn’t an on-off switch. What it needs to be is a dial, which can be turned up or down depending on what the data show on the ground in terms of how the Covid-19 epidemic is progressing.“Reopening is going to be a very complicated process, and it should be complicated,” he added. “Because this is about making sure that people don’t end up in the hospital or dying.”That California’s plan allows for counties to maintain stricter distancing guidelines or ease up measures could be both a strength and a liability.The flexibility has allowed hotspots like the Bay Area and Los Angeles to take a more cautious approach, but it has also already caused confusion. In San Diego, where curbside shopping has already begun, business owners were unsure what, if anything, would change on Friday. In Bakersfield, restaurants allowed patrons to dine in on Monday and Tuesday, in defiance of the state’s guidelines.A hodgepodge reopening could cause surges in cases; Californians who travel between more lax and more strict counties could spread infections. Moreover, a rush to reopen fast in some areas could be counterproductive to economic recovery, said Alessandro Rebucci, an economist at the Johns Hopkins Carey School of Business.“If you reopen when the pandemic is still out there, people and businesses will not just go back to normal,” Rebucci noted. Based on research from China, it seems clear that fear of contracting the illness will keep businesses owners and patrons home until they feel it’s safe enough, he said.

Patrick Herr
Apr 1, 2020; 19:608-623
Research

The cell cycle is a highly conserved process involving the coordinated separation of a single cell into two daughter cells. To relate transcriptional regulation across the cell cycle with oscillatory changes in protein abundance and activity, we carried out a proteome- and phospho-proteome-wide mass spectrometry profiling. We compared protein dynamics with gene transcription, revealing many transcriptionally regulated G2 mRNAs that only produce a protein shift after mitosis. Integration of CRISPR/Cas9 survivability studies further highlighted proteins essential for cell viability. Analyzing the dynamics of phosphorylation events and protein solubility dynamics over the cell cycle, we characterize predicted phospho-peptide motif distributions and predict cell cycle-dependent translocating proteins, as exemplified by the S-adenosylmethionine synthase MAT2A. Our study implicates this enzyme in translocating to the nucleus after the G1/S-checkpoint, which enables epigenetic histone methylation maintenance during DNA replication. Taken together, this data set provides a unique integrated resource with novel insights on cell cycle dynamics.

The transcription factor forkhead box P3 (FOXP3) is a biomarker for regulatory T cells and can also be expressed in cancer cells, but its function in cancer appears to be divergent. The role of hepatocyte-expressed FOXP3 in hepatocellular carcinoma (HCC) is unknown. Here, we collected tumor samples and clinical information from 115 HCC patients and used five human cancer cell lines. We examined FOXP3 mRNA sequences for mutations, used a luciferase assay to assess promoter activities of FOXP3's target genes, and employed mouse tumor models to confirm in vitro results. We detected mutations in the FKH domain of FOXP3 mRNAs in 33% of the HCC tumor tissues, but in none of the adjacent nontumor tissues. None of the mutations occurred at high frequency, indicating that they occurred randomly. Notably, the mutations were not detected in the corresponding regions of FOXP3 genomic DNA, and many of them resulted in amino acid substitutions in the FKH region, altering FOXP3's subcellular localization. FOXP3 delocalization from the nucleus to the cytoplasm caused loss of transcriptional regulation of its target genes, inactivated its tumor-inhibitory capability, and changed cellular responses to histone deacetylase (HDAC) inhibitors. More complex FKH mutations appeared to be associated with worse prognosis in HCC patients. We conclude that mutations in the FKH domain of FOXP3 mRNA frequently occur in HCC and that these mutations are caused by errors in transcription and are not derived from genomic DNA mutations. Our results suggest that transcriptional mutagenesis of FOXP3 plays a role in HCC.

Motor protein-based active transport is essential for mRNA localization and local translation in animal cells, yet how mRNA granules interact with motor proteins remains poorly understood. Using an unbiased yeast two–hybrid screen for interactions between murine RNA-binding proteins (RBPs) and motor proteins, here we identified protein interaction with APP tail-1 (PAT1) as a potential direct adapter between zipcode-binding protein 1 (ZBP1, a β-actin RBP) and the kinesin-I motor complex. The amino acid sequence of mouse PAT1 is similar to that of the kinesin light chain (KLC), and we found that PAT1 binds to KLC directly. Studying PAT1 in mouse primary hippocampal neuronal cultures from both sexes and using structured illumination microscopic imaging of these neurons, we observed that brain-derived neurotrophic factor (BDNF) enhances co-localization of dendritic ZBP1 and PAT1 within granules that also contain kinesin-I. PAT1 is essential for BDNF-stimulated neuronal growth cone development and dendritic protrusion formation, and we noted that ZBP1 and PAT1 co-locate along with β-actin mRNA in actively transported granules in living neurons. Acute disruption of the PAT1–ZBP1 interaction in neurons with PAT1 siRNA or a dominant-negative ZBP1 construct diminished localization of β-actin mRNA but not of Ca2+/calmodulin-dependent protein kinase IIα (CaMKIIα) mRNA in dendrites. The aberrant β-actin mRNA localization resulted in abnormal dendritic protrusions and growth cone dynamics. These results suggest a critical role for PAT1 in BDNF-induced β-actin mRNA transport during postnatal development and reveal a new molecular mechanism for mRNA localization in vertebrates.

In this interview from Preventing Overdiagnosis 2017 (preventingoverdiagnosis.net) Stacy Carter, associate professor at Sydney Health Ethics - and the author of a recently written BMJ essay the ethical aspects of overdiagnosis, joins us to talk about how the cultural context of medicine seeps into our decision making processes and affects how...

We aimed to assess the value of ¹¹C-choline PET in patients with primary hyperparathyroidism and negative or discordant results on ^99mTc-sestamibi imaging and neck ultrasound. Methods: Eighty-seven such patients were assessed and subsequently underwent parathyroidectomy. PET/CT image data were analyzed semiquantitatively using SUV_max and SUV ratios (target to contralateral thyroid gland and carotid artery). A positive PET/CT result was defined as focal uptake significantly higher than regular thyroid tissue. Ectopic foci were also considered positive. Inconclusive PET/CT cases were defined as a lesion with uptake equal to normal thyroid tissue. If no prominent or ectopic uptake was detectable, the PET/CT result was considered negative. Results: When dichotomizing the ¹¹C-choline PET/CT imaging results by defining lesions with both positive and inconclusive uptake as positive, we found 84 of 92 lesions (91.3%) to have true-positive uptake whereas 8 lesions (8.7%) had false-positive uptake. One lesion showed false-negative uptake; the sensitivity was 98.8%. The corresponding positive predictive value for lesions was 91.3%. The mean SUV_max was 6.15 ± 4.92 in 72 lesions with positive uptake (70 patients) and 2.96 ± 2.32 in 20 lesions with inconclusive uptake (18 patients). Conclusion: These results in a large group of patients indicate that ¹¹C-choline PET/CT is a promising tool for parathyroid adenoma localization when ultrasound and ^99mTc-sestamibi imaging yield negative or discordant results.

Primary hyperparathyroidism (PHPT) is a common endocrine disorder, definitive treatment usually requiring surgical removal of the offending parathyroid glands. To perform focused surgical approaches, it is necessary to localize all hyperfunctioning glands. The aim of the study was to compare the efficiency of established conventional scintigraphic imaging modalities with emerging ¹⁸F-fluorocholine PET/CT imaging in preoperative localization of hyperfunctioning parathyroid glands in a larger series of PHPT patients. Methods: In total, 103 patients with PHPT were imaged preoperatively with ¹⁸F-fluorocholine PET/CT and conventional scintigraphic imaging methods, consisting of ^99mTc-sestamibi SPECT/CT, ^99mTc-sestamibi/pertechnetate subtraction imaging, and ^99mTc-sestamibi dual-phase imaging. The results of histologic analysis, as well as intact parathyroid hormone and serum calcium values obtained 1 d after surgery and on follow-up, served as the standard of truth for evaluation of imaging results. Results: Diagnostic performance of ¹⁸F-fluorocholine PET/CT surpassed conventional scintigraphic methods (separately or combined), with calculated sensitivity of 92% for PET/CT and 39%–56% for conventional imaging (65% for conventional methods combined) in the entire patient group. Subgroup analysis, differentiating single and multiple hyperfunctioning parathyroid glands, showed PET/CT to be most valuable in the group with multiple hyperfunctioning glands, with sensitivity of 88%, whereas conventional imaging was significantly inferior, with sensitivity of 22%–34% (44% combined). Conclusion: ¹⁸F-fluorocholine PET/CT is a diagnostic modality superior to conventional imaging methods in patients with PHPT, allowing for accurate preoperative localization.

¹⁸F-DCFPyL (2-(3-{1-carboxy-5-[(6-¹⁸F-fluoropyridine-3-carbonyl)-amino]-pentyl}-ureido)-pentanedioic acid) is a promising PET radiopharmaceutical targeting prostate-specific membrane antigen (PSMA). We present our experience with this single-academic-center prospective study evaluating the positivity rate of ¹⁸F-DCFPyL PET/CT in patients with biochemical recurrence (BCR) of prostate cancer (PC). Methods: We prospectively enrolled 72 men (52–91 y old; mean ± SD, 71.5 ± 7.2) with BCR after primary definitive treatment with prostatectomy (n = 42) or radiotherapy (n = 30). The presence of lesions compatible with PC was evaluated by 2 independent readers. Fifty-nine patients had scans concurrent with at least one other conventional scan: bone scanning (24), CT (21), MR (20), ¹⁸F-fluciclovine PET/CT (18), or ¹⁸F-NaF PET (14). Findings from ¹⁸F-DCFPyL PET/CT were compared with those from other modalities. Impact on patient management based on ¹⁸F-DCFPyL PET/CT was recorded from clinical chart review. Results: ¹⁸F-DCFPyL PET/CT had an overall positivity rate of 85%, which increased with higher prostate-specific antigen (PSA) levels (ng/mL): 50% (PSA < 0.5), 69% (0.5 ≤ PSA < 1), 100% (1 ≤ PSA < 2), 91% (2 ≤ PSA < 5), and 96% (PSA ≥ 5). ¹⁸F-DCFPyL PET detected more lesions than conventional imaging. For anatomic imaging, 20 of 41 (49%) CT or MRI scans had findings congruent with ¹⁸F-DCFPyL, whereas ¹⁸F-DCFPyL PET was positive in 17 of 41 (41%) cases with negative CT or MRI findings. For bone imaging, 26 of 38 (68%) bone or ¹⁸F-NaF PET scans were congruent with ¹⁸F-DCFPyL PET, whereas ¹⁸F-DCFPyL PET localized bone lesions in 8 of 38 (21%) patients with negative results on bone or ¹⁸F-NaF PET scans. In 8 of 18 (44%) patients, ¹⁸F-fluciclovine PET had located the same lesions as did ¹⁸F-DCFPyL PET, whereas 5 of 18 (28%) patients with negative ¹⁸F-fluciclovine findings had positive ¹⁸F-DCFPyL PET findings and 1 of 18 (6%) patients with negative ¹⁸F-DCFPyL findings had uptake in the prostate bed on ¹⁸F-fluciclovine PET. In the remaining 4 of 18 (22%) patients, ¹⁸F-DCFPyL and ¹⁸F-fluciclovine scans showed different lesions. Lastly, 43 of 72 (60%) patients had treatment changes after ¹⁸F-DCFPyL PET and, most noticeably, 17 of these patients (24% total) had lesion localization only on ¹⁸F-DCFPyL PET, despite negative results on conventional imaging. Conclusion: ¹⁸F-DCFPyL PET/CT is a promising diagnostic tool in the work-up of biochemically recurrent PC, given the high positivity rate as compared with Food and Drug Administration–approved currently available imaging modalities and its impact on clinical management in 60% of patients.

A California 14-year-old who graduated high school at the age of 13 said she has now been accepted into the music programs at eight California universities.

Animal rescuers in California said they reached over the side of a freeway on-ramp to rescue a raccoon seen dangling from a metal beam under the ramp.

Navy leaders and private contractors broke ground this week on what will become the fleet's only dedicated facility to test, fire and evaluate complete laser weapon systems in a maritime environment.

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.

Two additional Delta Dental member companies announced details April 27-28 of programs that will provide economic assistance and post-COVID-19 pandemic relief for members of its independent provider networks across 16 states and the District of Columbia.

California, Iowa, Pennsylvania and Rhode Island are among states that are loosening coronavirus restrictions Friday to gradually revive their economies.

California Gov. Gavin Newsom on Friday signed an executive order requiring mail-in ballots be sent to all eligible voters for the November election.

The state leads the nation in poverty and homelessness while it's socialist elites live in absolute luxury. It's like some third world nation the US is obligated to invade on the basis of humanitarianism.

With pressure mounting on EU Member States to create and scale up refugee resettlement programs, many have turned to peers in other countries for information, advice, and operational support. This report maps the many forms resettlement-focused peer-support initiatives take and discusses common stumbling blocks and strategies for policymakers and program designers looking to make the most of these critical exchanges.

California classrooms could reopen with modifications as soon as late July, California Gov. Gavin Newsom said Tuesday, bringing a new wave of anxiety for parents, teachers, and students.

Aspiring teachers in California will now be able to major in education as undergraduates, which has been forbidden for more than five decades under an unusual state law.

Policy Analysis for California Education has been a premier ed policy organization for three decades. As Daisy Gonzales writes, it is in the forefront of shaping current reforms and interpreting them for audiences such as 'On California.'

The blessings of season to you all! We will be back in the New Year. Christmas thoughts follow.

Along with winter vegetables, STEM is blooming in Imperial County. Dennis and Daniel Gibbs are growing young scientists by transplanting the scientific method to the second grade.

Teachers unions are scapegoats for low student performance.

What's taking place in California is nothing less than a quiet revolution in education.

California just made school accountability much more complicated. And that's good.

California joins a growing number of cities and states hoping to spotlight which students do and do not have access to high-quality arts education.

Next year's California election will be both a referendum on the massive changes in education finance and testing enacted during Jerry Brown governorship and a test of the political coalition that made those changes possible.

As the number of charter schools continues to grow, voters in California will be forced to examine their largess.

A read of California's news outlets makes clear that the state is not going to accept President-elect Donald Trump's policies without a fight, particularly those on immigration.

State Assembly member Tony Thurmond ultimately prevailed over former charter school executive Marshall Tuck in a contest that drew more than $50 million in outside campaign spending.

Five California educators last week filed a lawsuit seeking to stop the state's top teachers' union from collecting dues through mandatory paycheck deductions.

Democrat Gavin Newsom, who takes office Jan. 7, plans to expand full-day kindergarten and child-care offerings in the state, according to media reports.

This Quality Counts 2019 Highlights Report captures all the data you need to assess your state's performance on key educational outcomes.

Lawmakers are considering legislation that would put limits on the state’s charter school sector and give districts broader discretion to deny applications.