Photo: Taken from the “glass-box” at the top of the Willis (Sears) Tower in downtown Chicago.
My name is Juan Martinez, and I have been part of the Hall lab since 2005. I was born in Colombia where I grew up, the land of coffee and football (the one you play with your feet). I originally came to the US as an exchange student and later obtained my B.S. degree in chemistry from Arkansas State University. At that point in time my main interests were molecular biology and cancer research, so I decided to pursue a Ph.D. degree. When I visited Purdue, I met with faculty members and found out that a lot of interesting and diverse research was going on in the department of Biochemistry. I was especially interested in the Hall lab because of the use of molecular biology to study cell cycle regulation and also because of the use of a very powerful research tool: mass spectrometry. It seemed that the focus of the lab was a good match for me.
One of the main interests of the lab is to study how the highly conserved ubiquitin ligase anaphase-promoting complex (APC) is regulated. The APC controls cell cycle progression by targeting a wide variety of regulatory proteins for destruction. It does so by attaching a chain of poly-ubiquitin to its substrates that is later recognized by the 26S proteasome. APC substrate selectivity is mediated by adaptor (or activator) proteins. Cdh1 is a tumor suppressor in humans that acts as an APC activator. It contributes to ubiquitination of mitotic cyclins and proteins involved in spindle integrity, basically helping cells to properly exit mitosis and begin the next cell cycle. In the lab, we discovered a specific inhibitor of the yeast APCCdh1, and we named it Acm1. Acm1 specifically associates with Cdh1 from S-phase to late mitosis with high affinity and prevents its interaction with substrates. I am currently involved in studying the biological role of Acm1, and also investigating how its own degradation is regulated. At the same time, I actively collaborate with other groups in and outside the department in projects that involve the use of mass spectrometry and proteomics in order to explore protein-protein interactions and post-translational modifications in different systems.
When not in the lab, I enjoy playing soccer, cooking and traveling. I also enjoy doing “field work” where I explore more rustic and flavorful yeast applications.