Diacylglycerol (DAG) is a key signaling lipid and intermediate in lipid metabolism. Our knowledge of DAG distribution and dynamics in cell membranes is limited. Using live‐cell fluorescence microscopy we investigated the localization of yeast cytosolic‐facing pools of DAG in response to conditions where lipid homeostasis and DAG levels were known to be altered. Two main pools were monitored over time using DAG sensors. One pool was associated with vacuolar membranes and the other localized to sites of polarized growth. Dynamic changes in DAG distribution were observed during resumption of growth from stationary phase, when DAG is used to support phospholipid synthesis for membrane proliferation. Vacuolar membranes experienced constant morphological changes displaying DAG enriched microdomains coexisting with liquid‐disordered areas demarcated by Vph1. Formation of these domains was dependent on triacylglycerol (TAG) lipolysis. DAG domains and puncta were closely connected to lipid droplets. Lack of conversion of DAG to phosphatidate in growth conditions dependent on TAG mobilization, led to the accumulation of DAG in a vacuolar‐associated compartment, impacting the polarized distribution of DAG at budding sites. DAG polarization was also regulated by phosphatidylserine synthesis/traffic and sphingolipid synthesis in the Golgi.

Mps3 is a SUN (Sad1-UNC-84) domain-containing protein that is located in the inner nuclear membrane (INM). Genetic screens with multiple Mps3 mutants have suggested that distinct regions of Mps3 function in relative isolation and underscore the broad involvement of Mps3 in multiple pathways including mitotic spindle formation, telomere maintenance, and lipid metabolism. These pathways have largely been characterized in isolation, without a holistic consideration for how key regulatory events within one pathway might impinge on other aspects of biology at the nuclear membrane. Mps3 is uniquely positioned to function in these multiple pathways as its N-terminus is in the nucleoplasm, where it is important for telomere anchoring at the nuclear periphery, and its C-terminus is in the lumen, where it has links with lipid metabolic processes. Emerging work suggests that the role of Mps3 in nuclear organization and lipid homeostasis are not independent, but more connected. For example, a failure in regulating Mps3 levels through the cell cycle leads to nuclear morphological abnormalities and loss of viability, suggesting a link between the N-terminal domain of Mps3 and nuclear envelope homeostasis. We will highlight work suggesting that Mps3 is pivotal factor in communicating events between the nucleus and the lipid bilayer.

Effective communication is one of the most marketable and transferable skills a graduate can have. Unfortunately, science programs rarely develop effective writing skills due to the time‐consuming nature of evaluating these skills. Here, we try to adapt tools from specifications grading to simplify marking and maximize student success in a third‐year biochemistry lab techniques course. We provided feedback to students on whether or not they were writing to the expected level on short lab reports so that they could implement it in a cumulative lab report. Students struggled to accept the all or none nature of specifications grading and did better with a writing workshop and one‐on‐one feedback. Overall, writing improved the most in sections where students received the most practice. We observed moderate success in improving writing skills in class size of 35, which is larger than most previous exercises of this nature. Support or Funding Information Thank you to Kyle McDade and Ryan Toth for their help in grading.

The nuclear envelope (NE) is important in maintaining genome organization. The role of lipids in communication between the NE and telomere regulation was investigated, including how changes in lipid composition impact gene expression and overall nuclear architecture. Yeast was treated with the non-metabolizable lysophosphatidylcholine analog edelfosine, known to accumulate at the perinuclear ER. Edelfosine induced NE deformation and disrupted telomere clustering but not anchoring. Additionally, the association of Sir4 at telomeres decreased. RNA-seq analysis showed altered expression of Sir-dependent genes located at sub-telomeric (0–10 kb) regions, consistent with Sir4 dispersion. Transcriptomic analysis revealed that two lipid metabolic circuits were activated in response to edelfosine, one mediated by the membrane sensing transcription factors, Spt23/Mga2, and the other by a transcriptional repressor, Opi1. Activation of these transcriptional programs resulted in higher levels of unsaturated fatty acids and the formation of nuclear lipid droplets. Interestingly, cells lacking Sir proteins displayed resistance to unsaturated-fatty acids and edelfosine, and this phenotype was connected to Rap1.

The transport and regulation of metals in eukaryotic cells is a complex process, dependent on protein transporters that respond to cell needs. The application of dynamic mathematical models can provide valuable insights into these transport mechanisms. Mathematical simulations of transport processes may not directly predict transport mechanisms but can guide experimental design or identify inconsistencies between observation and hypotheses. Copper is an essential metal in eukaryotic cells as a catalytic co-factor in metallochaperone proteins and is therefore tightly regulated in living systems, making it valuable for quantifying biological transport mechanisms. In order to test our modeling system, a culture of baker’s yeast (Saccharomyces cerevisiae) was grown, copper concentrations were obtained from the cells and growth media, and a mathematical model was developed to investigate transport mechanisms between the growth media and the cells. A model based on conservation of mass was presented as a system of equations upon which to develop. This system of equations was developed to include an active transport term that describes a homeostatic concentration that cells actively maintain through negative feedback, and with a delayed activation, the model was more accurate at predicting the experimental data. The hypothesis and dynamic model derived in this work provide a novel framework that may be applied to additional metals or used to describe other transport mechanisms in biological systems.