Analysis of conserved residues in the betapat-3 cytoplasmic tail reveals important functions of integrin in multiple tissues.

Integrin cytoplasmic tails contain motifs that link extracellular information to cell behavior such as cell migration and contraction. To investigate the cell functions mediated by the conserved motifs, we created mutations in the Caenorhabditis elegans betapat-3 cytoplasmic tail. The beta1D (799FK800), NPXY, tryptophan (784W), and threonine (797TT798) motifs were disrupted to identify their functions in vivo. Animals expressing integrins with disrupted NPXY motifs were viable, but displayed distal tip cell migration and ovulation defects. The conserved threonines were required for gonad migration and contraction as well as tail morphogenesis, whereas disruption of the beta1D and tryptophan motifs produced only mild defects. To abolish multiple conserved motifs, a beta1C-like variant, which results in a frameshift, was constructed. The betapat-3(beta1C) transgenic animals showed cold-sensitive larval arrests and defective muscle structure and gonad migration and contraction. Our study suggests that the conserved NPXY and TT motifs play important roles in the tissue-specific function of integrin.

History of the biomedical studies PhD program: a joint graduate program of the Baylor Health Care system and Baylor University.

On a sweltering summer morning, throngs of people filed into Jones Theatre at Baylor University in Waco for the graduate student orientation. One could look around and notice the diversity of not only the student population, but also the disciplines being represented. Many students had stepped off planes only hours prior, but even those who had been traveling for days could not contain their excitement. As for me, I was nowhere near any of this. I was still 40 miles north of Waco in Waxahachie, having been pulled over for speeding. After 4 days of traveling with my life in my Volkswagon Jetta, all the way from San Francisco, on one of the most important days of my life, I was late. When I finally arrived at the Hooper Schafer Fine Arts Auditorium, out of breath from running all the way from the parking structure, all of the graduate students were quietly listening to the first introductory speech. I snuck into the back and sat down. My mind was racing, as I knew very little about Waco and Baylor University except for the growing accomplishments of the biomedical studies program. What little I did know about Baylor seemed so different from my very liberal upbringing in California. What would this experience be like for me? But, as I listened to the talks, met with other students, and finally met the entire biomedical studies entering class of 2007, I knew that I had made the right decision in coming to Baylor. This would be an experience unlike any other, and I was wholeheartedly open to embracing it. -Christine Morel, PhD candidate, Institute of Biomedical Studies.