Ribonuclease P (RNase P) is an essential endonuclease responsible for catalyzing 5’ end maturation in precursor transfer RNAs. Since its discovery in the 1970s, RNase P enzymes have been identified and studied throughout the three domains of life. Interestingly, RNase P is either RNA-based, with a catalytic RNA subunit, or a protein-only (PRORP) enzyme with differential evolutionary distribution. The available structural data, including the active site data, provides insight into catalysis and substrate recognition. The hydrolytic and kinetic mechanisms of the two forms of RNase P enzymes are similar, yet features unique to the RNA-based and PRORP enzymes are consistent with different evolutionary origins. The various RNase P enzymes, in addition to their primary role in tRNA 5’ maturation, catalyze cleavage of a variety of alternative substrates, indicating a diversification of RNase P function in vivo. The review concludes with a discussion of recent advances and interesting research directions in the field.

A 3-week module incorporating the principles of green chemistry was developed for a large-enrollment, introductory organic chemistry laboratory course. An emphasis was placed on students planning their own experiments with the goal of obtaining a greener reaction (week 1). Students executed their designed experiments in week 2 and were given an opportunity to repeat the experiment or further optimize the reaction conditions to improve the yields during week 3. A postlab writing assignment as well as pre-and postsemester surveys were used to evaluate student learning and confidence. These data revealed an increase in students' understanding of green chemistry concepts as well as their confidence in their ability to modify a reaction to improve the results. We anticipate that this overall framework can be adapted to other large-and small-enrollment laboratory courses.

The human cerebrovascular system is responsible for regulating demand-dependent perfusion and maintaining the blood-brain barrier (BBB). In addition, defects in the human cerebrovasculature lead to stroke, intracerebral hemorrhage, vascular malformations, and vascular cognitive impairment. The objective of this study was to discover new proteins of the human cerebrovascular system using expression data from the Human Protein Atlas, a large-scale project which allows public access to immunohistochemical analysis of human tissues. We screened 20,158 proteins in the HPA and identified 346 expression patterns correlating to blood vessels in human brain. Independent experiments showed that 51/52 of these distributions could be experimentally replicated across different brain samples. Some proteins (40%) demonstrated endothelial cell (EC)-enriched expression, while others were expressed primarily in vascular smooth muscle cells (VSMC; 18%); 39% of these proteins were expressed in both cell types. Most brain EC markers were tissue oligospecific; that is, they were expressed in endothelia in an average of 4.8 out of 9 organs examined. Although most markers expressed in endothelial cells of the brain were present in all cerebral capillaries, a significant number (21%) were expressed only in a fraction of brain capillaries within each brain sample. Among proteins found in cerebral VSMC, virtually all were also expressed in peripheral VSMC and in non-vascular smooth muscle cells (SMC). Only one was potentially brain specific: VHL (Von Hippel-Lindau tumor suppressor). HRC (histidine rich calcium binding protein) and VHL were restricted to VSMC and not found in non-vascular tissues such as uterus or gut. In conclusion, we define a set of brain vascular proteins that could be relevant to understanding the unique physiology and pathophysiology of the human cerebrovasculature. This set of proteins defines inter-organ molecular differences in the vasculature and confirms the broad heterogeneity of vascular cells within the brain.

Introductory-level laboratory courses provide students with hands-on experience using the discipline's tools and theories. These courses often rely on recipebased experiments due to the constraints of large enrollments, short lab periods, and the desire to minimize complexity. In addition, covering a breadth of topics can lead to a fragmented curriculum with little carryover in learning from week to week. Herein, we describe an overhaul of an introductory organic chemistry laboratory curriculum, informed by the strategies of meaningful learning and a desire to make the course experience mimic a research lab. This new course, primarily taught to first-year undergraduate students at the University of Michigan, is framed with three interconnected modules. We present herein the first module, which focuses on thinlayer chromatography (TLC). In the first week, students learn how to perform TLC using a variety of compounds and solvent mixtures, gaining an understanding of how intermolecular interactions affect their retention. In the second week, they practice using TLC to distinguish reagents and reaction byproducts and in the third week apply TLC to monitor reaction progress and test their hypothesis. We assessed student learning through a writing assignment at the end of the three-week module. We also assessed how the overall course affects student comprehension of TLC concepts and confidence. Our findings suggest that this learn, practice, apply approach toward teaching introductory organic chemistry laboratory concepts leads to learning gains and increased confidence.