Activities

The James and Kathleen McCloskey Bioscience Endowed Lecture is an annual highlight for us. This year was no exception, as we were honored to hear from one of our own – Dr. William “Bil” M. Clemons, Jr. Bil was a graduate student with Venki Ramakrishnan in our department from 1995 – 2000. In 1999, they and their colleagues published the structure of the small subunit of the bacterial ribosome to great fanfare, with Bil as the first author. It was an amazing triumph, and it laid the initial foundat ion for Venki’s 2009 Nobel Prize in Chemistry. After a very successful postdoc at Harvard, Bil started his own lab at Caltech in 2005, where he has been ever since. Important discoveries have continued to flow from his lab, and we were all delighted and proud when Bil was elected to the National Academy of Sciences last spring. Bil and Jim McCloskey knew one another well when Bil was a student here, and it was therefore especially meaningful that Kay McCloskey and her family were able to attend the lecture. Bil began his lecture by reminding us of the From left to right: Lydia McCloskey, Kay McCloskey, Bil Clemons, Gus McCloskey, Pam Crain, Wes Sundquist, and Chris Hill. Photo credit: Janet Iwasa. historic societal inequities that have unfairly impeded the progress and recognition of scientists of color, and pointed out that we each have a responsibility to help rectify those injustices. Importantly, such discrimination isn’t just a problem that occurred in some distant place, but rather has been ubiquitous, including with tangible local examples. For example, most of us learned for the first time that the initial settlers of our valley by European Americans included slave owners.  Bil’s comments were an important reminder of the obligation that we all have to help ensure that the injustices of the past don’t continue into the future, and that science advances as quickly and fairly as possible by taking advantage of our full talent pool. Bil also described his laboratory’s elegant structure/function studies of the cellular GET (guided entry of TA proteins) pathway. The GET pathway ensures that proteins with single transmembrane sequences located near their C-termini (called “tail-anchored” or TA proteins) traffic to the correct cellular organelle (typically the ER). This is a problem that requires a special dedicated system because, unlike proteins with N-terminal transmembrane helices, TA proteins cannot be made on ER-associated ribosomes and co-translationally inserted into the ER membrane. Bil reviewed several of his lab’s important contributions in this area, including defining: 1) how the Get4-Get5 complex mediates the handover of TA substrates from the co-chaperone Sgt2 to the central targeting factor, Get3, and 2) how GET3 uses ATP binding, hydrolysis and release to drive dramatic conformational changes that allow it to bind, deliver, and release client proteins to the correct location. His lecture was a wonderful tour of this remarkable protein chaperoning system.