Wednesday, July 2, 2008

My usual workdays: Sonic Hedgehogs and Chinese Food Truck

Every day in lab I play outdated video games while relentlessly stuffing myself with cheap Chinese food. I wish. Well, maybe the latter is true, or partially at least.

The Sonic Hedgehogs I work with are actually a very serious subject matter. Far from being animated blue characters coasting across a computer game screen in search for golden rings, the Sonic Hedgehogs in my lab are proteins crucial to skeletal, muscle, brain, and gastrointestinal development during the formation of embryos. Defects in the Sonic Hedgehog signaling pathway can lead to severe deformations, most strikingly cyclopia, the fusion of the two eyes. In animals such as mice and flies (the scientifically ubiquitous Drosophila melanogaster), impaired, absent, or abnormally expressed Sonic Hedgehog proteins can lead to missing or misplaced limbs and neurological damage.

The protein's playful name clashes with the grave consequences of its malfunction. From what I gather, a science ethics and nomenclature committee has been established to review facetious names such as this one in order to re-instill seriousness into such serious science topics in. Imagine a doctor telling you that your birth defects result from a faulty Sonic Hedgehog!

Anyway, back to what I am actually researching in the lab. This summer, my broad goal is to expand our knowledge of the molecular biology of the Sonic Hedgehog signaling pathway. Why do we want to know more about the mechanism through which the protein operates? Well, insight into how the protein normally affects cell activity can elucidate how defects in the signaling pathway originate and how do they disrupt cell metabolism. Such knowledge help scientists combat the Sonic Hedgehog related disorders. Furthermore, Sonic Hedgehog activity has been linked to certain forms of cancer and stem cell differentiation, two closely and mysteriously intertwined fields in biomedical science that only recently have gained attention as two sides of the same coin. This protein is so important to embryogenesis that to understand early development, we must understand its behavior and the molecular dynamics of its associated signaling pathways.

Enough of this fluffy talk and down to the nitty-gritty: During the ten weeks of PRISE, I will be tracking down three of the cell membrane receptors of the hedgehog protein, namely Cdo, Boc, and Gas1. Among other cell surface receptors, these three receptors are important for the protein outside the cell to relay information into the cell. Right now, I've been transfecting cells (NIH 3T3 cell line of mice fibroblasts) with DNA constructs to knockdown and overexpress Cdo, and then treating cells with a hedgehog agonist to analyze the amount of cell signaling in the hedgehog transcriptional pathway (with a luciferase assay - practically speaking measuring luminescence levels).

Further along the project I will used receptor DNA constructs fused with green fluorescence protein (GFP) and examine the localization of my three receptors on the cell surface (the differences in receptor distribution on the cell membrane and reveal a lot about signaling activity between the extracellular hedgehog protein and molecules inside the cell). Eventually, I will also be able to "pull down" the receptors from the membrane and characterize them through mass spectroscopy to identify other protein complexes that are associated with these receptors (and are consequently pulled down with them).

This is a very exciting work, and I can't wait to get to the live imaging step. How amazing is it to watch microscopic receptors move around on the cell membrane?!

So, besides doing transfections, cell culture, and unhealthy amounts of pipetting, I enjoy talking to other lab members about their research, and their life histories (which I must say are quite interesting). And who can forget the infamous Chinese Food Truck, enticingly parked on Oxford Street.

The funny thing is that they person who interacts with the customers is Hspanic (the cooks are Chinese though). While the food is delicious and cheap, I'm sure it's not contributing to my longevity. Right now, gastronomic delight trumps my concern for clogged arteries. Bad modus vivendi, perhaps?

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