Intracellular Lipid Homeostasis and Trafficking in Autophagy

In eukaryotes, lipids are not only an important constituent of the plasma membrane but also used to generate specialized membrane-bound organelles, including temporary compartments with critical functions. As such, lipids play a key role in intracellular homeostasis—the ability of a cell to maintain stable internal conditions upon changes in its extracellular environment. Autophagy, one of the cellular processes through which eukaryotic cells strive for survival under stress, is heavily dependent on lipid and membrane trafficking through the de novo formation of autophagosomes—temporary, large, and double-bilayered organelles in which materials are encapsulated for recycling. This chapter discusses what we know about lipid homeostasis and trafficking during autophagy and autophagosome formation and comments on future directions of the field

Biochemical markers of bone turnover and clinical outcome in patients with renal cell and bladder carcinoma with bone metastases following treatment with zoledronic acid: The TUGAMO study

Background: Levels of bone turnover markers (BTM) might be correlated with outcome in terms of skeletal-related events (SRE), disease progression, and death in patients with bladder cancer (BC) and renal cell carcinoma (RCC) with bone metastases (BM). We try to evaluate this possible correlation in patients who receive treatment with zoledronic acid (ZOL). Methods: This observational, prospective, and multicenter study analysed BTM and clinical outcome in these patients. Serum levels of bone alkaline phosphatase (BALP), procollagen type I amino-terminal propeptide (PINP), and beta-isomer of carboxyterminal telopeptide of type I collagen (b-CTX) were analysed. Results: Patients with RCC who died or progressed had higher baseline b-CTX levels and those who experienced SRE during follow-up showed high baseline BALP levels. In BC, a poor rate of survival was related with high baseline b-CTX and BALP levels, and new SRE with increased PINP levels. Cox univariate analysis showed that b-CTX levels were associated with higher mortality and disease progression in RCC and higher mortality in BC. Bone alkaline phosphatase was associated with increased risk of premature SRE appearance in RCC and death in BC. Conclusion: Beta-isomer of carboxy-terminal telopeptide of type I collagen and BALP can be considered a complementary tool for prediction of clinical outcomes in patients with BC and RCC with BM treated with ZOLNovartis Oncology Spain for supporting this stud

Usefulness of bone turnover markers as predictors of mortality risk, disease progression and skeletal-related events appearance in patients with prostate cancer with bone metastases following treatment with zoledronic acid: TUGAMO study

Owing to the limited validity of clinical data on the treatment of prostate cancer (PCa) and bone metastases, biochemical markers are a promising tool for predicting survival, disease progression and skeletal-related events (SREs) in these patients. The aim of this study was to evaluate the predictive capacity of biochemical markers of bone turnover for mortality risk, disease progression and SREs in patients with PCa and bone metastases undergoing treatment with zoledronic acid (ZA). Methods: This was an observational, prospective and multicenter study in which ninety-eight patients were included. Patients were treated with ZA (4mg every 4 weeks for 18 months). Data were collected at baseline and 3, 6, 9, 12, 15 and 18 months after the beginning of treatment. Serum levels of bone alkaline phosphtase (BALP), aminoterminal propeptide of procollagen type I (P1NP) and beta-isomer of carboxiterminal telopeptide of collagen I (b-CTX) were analysed at all points in the study. Data on disease progression, SREs development and survival were recorded. Results: Cox regression models with clinical data and bone markers showed that the levels of the three markers studied were predictive of survival time, with b-CTX being especially powerful, in which a lack of normalisation in visit 1 (3 months after the beginning of treatment) showed a 6.3-times more risk for death than in normalised patients. Levels of these markers were also predictive for SREs, although in this case BALP and P1NP proved to be better predictors. We did not find any relationship between bone markers and disease progression. Conclusion: In patients with PCa and bone metastases treated with ZA, b-CTX and P1NP can be considered suitable predictors for mortality risk, while BALP and P1NP are appropriate for SREs. The levels of these biomarkers 3 months after the beginning of treatment are especially importantThis study was supported by Novartis Oncology Spai

Rolling Circle Mutagenesis of GST-mCherry to Understand Mutation, Gene Expression, and Regulation

Undergraduates are often familiar with textbook examples of human mutations that affect coding regions and the subsequent disorders, but they may struggle with understanding the implications of mutations in the regulatory regions of genes. We have designed a laboratory sequence that will allow students to explore the effect random mutagenesis can have on protein function, expression, and ultimately phenotype. Students design and perform a safe and time-efficient random mutagenesis experiment using error-prone rolling circular amplification of a plasmid expressing the inducible fusion protein glutathione S-transferase (GST)-mCherry. Mutagenized and wild-type control plasmid DNA, respectively, are then purified and transformed into bacteria to assess phenotypic changes. While bacteria transformed with the wild type control should be pink, some bacterial colonies transformed with mutagenized plasmids will exhibit a different color. Students attempt to identify their mutations by isolating plasmid from these mutant colonies, sequencing, and comparing their mutant sequence to the wild-type sequence. Additionally, students evaluate the potential effects of mutations on protein production by inducing GST-mCherry expression in cultures, generating cell lysates, and analyzing them using SDS-PAGE. Students who have a phenotypic difference but do not obtain a coding region mutation will be able to think critically about plasmid structure and regulation outside of the gene sequence. Students who do not obtain bacterial transformants have the chance to contemplate how mutation of antibiotic resistance genes or replication origins may have contributed to their results. Overall, this series of laboratories exposes students to basic genetic techniques and helps them conceptualize mutation beyond coding regions

Atg27p co-fractionates with clathrin-coated vesicles in budding yeast

Atg27p, a single-pass transmembrane protein that functions in autophagy, localizes to a variety of cellular compartments including the pre-autophagosomal structure, late Golgi, vacuolar membrane, as well as early and late endosomes. Its cytoplasmic C-terminus contains a tyrosine sorting motif that allows for its transport to the vacuolar membrane and an additional sequence that allows for its retrieval from the vacuolar membrane to the endosome. Since clathrin is well known to mediate vesicular transport in the endomembrane system, the trafficking of Atg27p and its tyrosine sorting motif suggested that it might be trafficked inside clathrin-coated vesicles (CCVs). In our previous studies, Atg27p was identified by mass spectrometry as a potential component in CCVs, as it was present in CCVs isolated from both WT and auxilin-depleted cells. We now confirm that Atg27p is a component of CCVs using immunoblotting and additional mass spectrometry data

Applied Theatre Facilitates Dialogue about Career Challenges for Scientists

The design of programs in support of a strong, diverse, and inclusive scientific workforce and academe requires numerous difficult conversations about sensitive topics such as the challenges scientists can face in their professional development. Theatre can be an interactive and effective way to foster discussion around such subjects. This article examines the implementation and benefits of such interactive strategies in different contexts, including the benefits of getting early career academics and professionals talking about some of the situations that women and underrepresented minorities face in the workplace, while allowing more seasoned professionals and colleagues to join in the conversation

Extended Data 1: Atg27p co-fractionates with clathrin-coated vesicles in budding yeast

CCVs clathrin null strain, all mass spectrometry hits, sorted, and with abbreviated information per slice.Related Publication: Atg27p co-fractionates with clathrin-coated vesicles in budding yeast Verónica A. Segarra Department of Biology, High Point University, High Point, NC, USA 27268 microPublication Biology 2021-03-26 https://doi.org/10.17912/micropub.biology.000380 engContact person: Verónica A. Segarra [email protected]