September 2013

Gut bacteria may be a source of male steroid hormones

Looks like there is more than one fount for male steroid hormones in the body. In a paper recently out in the Journal of Lipid Research, researchers show that a bacterial species converts glucocorticoids into androgens, a group of male steroid hormones. The implication is that the host endocrine system may not be the only source of androgens and other regulatory molecules: The gut microbiome may be another.


Introducing the monkey sperm proteome

We now have the sperm proteome of a primate. In a paper in Molecular & Cellular Proteomics, researchers describe the sperm proteome of the rhesus macaque, the first primate to have its sperm proteome analyzed. Sperm proteomes from nonprimate species, such as rats, mice and fruit flies, already have been determined. “For comparative evolutionary and functional genomics studies, a primate sperm proteome was highly desirable to include in this growing list of sperm proteomes,” explains Tim Karr at Arizona State University.


Proteins need chaperones, too

“I remember walking down the hill to grab breakfast after an overnight fire drill with putting up image plates, shooting X-rays, then fetching the plates and putting them into the Fuji scanner at the F1 beamline … thinking, ‘This is really going to change our understanding of this machine.’” This is how Arthur Horwich relates the excitement during his first data collection on the GroEL protein at the Cornell High Energy Synchrotron Source. Describing his 20-year scientific adventure with the protein-folding machine in his recent Reflections article in The Journal of Biological Chemistry, Horwich takes readers through the initial discovery of the chaperonin, its structural analyses and elucidation of its mechanism.


Chlamydial virulence factor structure 'very odd indeed'

A protein secreted by Chlamydia trachomatis, the bacterium that causes chlamydia, has an unusual structure, according to scientists in the School of Medicine at The University of Texas Health Science Center San Antonio. The shape of the protein Pgp3 is distinctive — sort of like an Eiffel Tower of proteins.


Making a new ring every 20 minutes

Cell division, the final stage of the bacterial cell cycle, involves a network of molecules to control the position of the division machinery, the divisome, at midcell. In E. coli, a bacterium that lives in our gut, the initial assembly of the division machinery requires three major proteins, FtsZ, FtsA and ZipA, and together these proteins form the proto-ring at midcell. In a recent minireview published in The Journal of Biological Chemistry, researchers at the Centro Nacional de Biotecnologia in Madrid describe the importance of these proteins in the formation, maturation, stabilization and function of the E. coli division machinery.


Plants use a network of modifying enzymes to control hormone action

The effects of plant hormones, such as ethylene, auxins or gibberellins, are crucial to the proper growth and development of plants. Equally important, however, is the biochemical regulation of plant hormones in synthesis and modification. In a recent minireview published in The Journal of Biological Chemistry, Corey S. Westfall and colleagues at Washington University in St. Louis highlight the key enzymatic players in hormone regulation, noting the remarkable evolutionary conservation of families of regulatory enzymes as well as the intricate network needed to turn hormones on and off at just the right time.


Thematic series explores biochemical diversity of cytochrome P450 enzymes

A recent thematic series on cytochromes P450 in The Journal of Biological Chemistry consists of four minireviews covering new trends in P450 research and the many roles they play in disease. As important catalysts involved in hormone and drug biochemistry, these diverse enzymes are the center of attention in a number important fields. In his introduction to the series, coordinating editor F. Peter Guengerich of Vanderbilt University illustrates how the P450 field has matured over the past 50 years. “With (more than) 18,000 known P450 sequences available and the number increasingly rapidly,” Guengerich writes, “it is humbling to realize that we understand the functions of only a fraction of these P450s.”


Grant-writing workshop recap

Two years ago, the American Society for Biochemistry and Molecular Biology Minority Affairs Committee embarked on an initiative to identify the perceived barriers encountered by faculty members from groups that are underrepresented in the sciences and by faculty members at minority-serving institutions. Although the committee identified several barriers, including an opaque review process, lack of a support network, a leaky pipeline of minority talent and a lack of initiatives directed at underrepresented minorities, the underlying issue common to all participants in the working group was the lack of formal mentoring.


Demystifying the chalk talk

A chalk talk is your opportunity to present your forward-looking research program to potential colleagues. They will have seen your seminar on the first day, so your research accomplishments will be fresh on their minds. They will be wondering how you plan to organize your laboratory, what types of experiments you plan to do first, what your funding plans are, what your relationship is with your current principal investigator, who you think your major competition is and how well you have thought out your research plans in case things don’t work out the way you think they will.


What, how and why is problem-based learning in medical education?

Problem-based learning is a pedagogical practice employed in many medical schools. While there are numerous variants of the technique, the approach includes the presentation of an applied problem to a small group of students who engage in discussion over several sessions.


Speaking of fat: ASBMB 2014 meeting in San Diego

Communication is a cornerstone of scientific advances. I’ve always maintained that a large part of science is a dialogue among colleagues within and across disciplines. That’s one of the important aspects of the annual American Society for Biochemistry and Molecular Biology meeting. It provides a mechanism for stimulating disciplinary and interdisciplinary discussions among established investigators, new investigators and, perhaps most importantly, budding investigators. In the lipid community, we take this opportunity seriously and work hard to provide a spirited camaraderie that welcomes ideas and inputs for all investigators within and outside our discipline.


Special symposium recap: evolution and core processes in gene expression

A major achievement of 20th-century biology was the identification of the fundamental, shared genetic and biochemical properties of all life forms. Now, understanding the nature of biological variation at the population and species levels represents a core question in modern biological research, one that spans disciplines from genetics to biochemistry and genomics. Which cellular processes are most commonly affected to generate diverse phenotypes?


Bringing science to the people

David J. Kroll writes: "At the North Carolina Museum of Natural Sciences in Raleigh, you wouldn’t even have to go outside of your floor to show off your mad skills to the public. With floor-to-ceiling glass walls, comfy bench seating in front of the lab and interactive touch-screen videos playing on the lab glass, visitors to the Southeast’s largest venue of its kind can learn about the scientific process while it happens."


Starting salaries: how to ask for more and to launch a negotiation

Karen Kelsky writes: "Academics tend to struggle with negotiating job offers because of the enduring monkish quality of the scholarly life, which is ideally meant to forsake material gain for a higher calling of dedication to the truth. How this ideal has endured to 2013 is beyond me, but endured it has, and it does a tremendous disservice to the young Ph.D.s attempting to finalize the terms of their first professional positions."


How to compete with a lab diva

We all know them — research minions, professor’s pets, lab divas — those bench mates who seem to get all the attention and resources even though you are just as talented as they are. They often exhibit selfish behavior (e.g., leave common lab spaces messy, use up lab supplies, etc.), and for some reason, the principal investigator seems to reward them for this science superstar attitude, creating a perception of lab favoritism among team members.

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