A Symposium on the Cytoskeleton

In conjunction with the 11th Annual Student Research Day, three distinguished speakers were on hand to talk about their specialties on February 25, 1999.  This was held by the Graduate School of Biomedical Sciences at the Texas Tech University Health Sciences Center in room 5B148A.


"Control of Endocytosis by Dynamin"

The first speaker was Joseph P. Albanesi, Ph.D., who is an associate professor at the University of Texas Southwestern Medical Center, in Dallas, Texas.  He began his presentation by crediting Howard S. Shpetner and Richard B. Vallee for their discovery of the large motor protein, dynamin, 10 years ago.  Dr. Albanesi continued with related dynamin topics by talking about the Drosophila shibire mutant, which was found to have paralysis due to inadequate recycling of synaptic vesicles.  He spent the majority of his talk dealing with dynamin's role in rapid endocytosis.  This protein approaches the invagination precursor along with other factors to stimulate vesicle formation.  The big question that has risen in the past is whether it is a pinchase or more like a G-protein.  One dynamin protein can actually activate another dynamin protein.  Its GTPase activity was related to the concentration of dynamin.  The graph he showed look somewhat similar to the enzyme kinetics curve our class had studied.  A dynamin protein was shown to be regulated by phosphorylation.  A phosphate on the 5 position activated it.  Some of the information that we had covered in our class was found in this talk (as well as others) including primary structure, various amino acids, C and N termini, and binding by conformation.  Many of the computer generated diagrams were very descriptive and colorful allowing the audience to see what he was describing.


"Regulation of Cytoskeletal Structure and Function By Signal Transduction Proteins"

George S. Bloom, Ph.D., is a full professor also from the University of Texas Southwestern Medical Center, in Dallas, Texas.  He used interesting visual aids to describe secretory pathways.  He described the microtubules as an intracellular highway.  I remember seeing one of his visual aids represented by a car headed towards a plus sign.  This was labeled "kinesins only" since they are the main microtubule motor proteins for movement towards the plasma membrane.  A "70's car" with painted flowers on it was driving towards the microtubule organizing center represented by a minus sign.  This was labeled dyneins and some kinesins.  I was very impressed with the quicktime videos that showed pieces of the golgi and thin strands of cytoskeleton microfilaments moving around.  You could actually make out the thin lines that went in different directions.  During the last half of Dr. Bloom's talk, he included a graph comparing the length of a tubule to time.  Also, he talked about various trimeric G-protein probes that do not inhibit motility, probes for small G-proteins that inhibit tubulation, and probes for small G-proteins that have no effect.  When describing centrifugation and purification methods used in his lab, a detergent (Triton X-100) that we had covered in our class was mentioned.


"Myosin Family of Actin Based Molecular Motors: Tails of Blindness, Deafness, and Seizures"

Mark Mooseker, Ph.D., is the current Ross Granville Harrison Professor at Yale University.  He began by informing the audience that he would cut out parts of the lecture including the blindness and deafness portions.  Myosin II and V were covered in more detail than other types (currently 15 in all, soon to officially be 16 in total).  Myosin II is short so it works in teams while myosin IV has long necks with "cervical" collars that allow for it to work alone effectively.  The biomechanics and the three sections (tail, neck, and head domains) of myosins were reviewed .  He spoke of surface loops in the tail region that gave different myosins structural variation and different enzymatic mechanochemical and/or regulational properties.  This reminded me of the 6 small surface loops on immunoglobulins that we had talked about in class.  What impressed me the most about Dr. Mooseker's talk was that he used actual objects as visual aids which may not have been as extravagant as computer generated diagrams, but they did the job well, maybe even better.  A flat piece of cardboard with protein structure drawn on it had thread and wire attached to it so that everyone could see the various parts in three dimensions.  He also had two balloons (that represented the motor head domains) taped to a stick.  He used this model along with a cardboard cylinder (with parts of it labeled) to show myosin interactions.  He probably kept our attention the best by actually jumping around and using different tones of his voice to show myosin movements and their varying degrees. 


In these talks, some of the details discussed were too complicated for me to comprehend, but the basics of cell biology were still there.  Sometimes I would hear words that sounded faintly familiar, but some of the others were actually the same as what we had learned in class (and I have linked them to the rest of my cell pages).  I was privileged to be a part of three fantastic lectures by professors from other parts of the country.  I noticed how all three speakers were successful with using humor to lighten the mood.  Analogies in layman's terms were common, but the speakers also communicated easily with technical vocabulary that they and their colleagues were familiar with.  I saw the professionalism in the field by their eagerness to give credit to fellow workers (from grad students to fellow Ph.D.'s) and competitors.  I learned that being in this field requires a great deal of commitment after seeing the great amount of information presented and after reading over the synopsis of their education and time spent in cell biology.  I was fortunate enough to speak with Dr. Mooseker who also does some teaching at the medical school at Yale.  I inquired on what it took for "a kid from West Texas who attends Texas Tech" to get into their medical school.  Of course, the usual requirement of grades and MCAT scores was talked about, but one unique piece of advice I received on this day was the suggestion of taking a few years out of school to work in a research laboratory at Yale.  He told me this would give me great scientific experiences, relationships with distinguished faculty, and a growth in maturity.  I had never considered dropping out of school for a few years to increase my chances for medical school.  Overall I was able to listen to talks that I do not usually experience and get some specific information on my personal goals.  Chatting with Dr. Mooseker for fifteen minutes at the end of the day was my favorite part of the whole symposium. 
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