Research Group of Professor Ian Macara, University of Virginia

Research Group of Professor Ian Macara, University of Virginia

Ian Macara is Professor of Microbiology at the University of Virginia, Center for Cell Signaling. He has recently been made the Director of the Advanced Microscopy Facility which serves many departments at the University. In addition he leads a team of scientists researching the molecular basis of cell asymmetries. One key goal is to understand the cellular functions of small GTP binding proteins.

GTP binding proteins act as molecular switches. They control a wide range of biological processes including receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their function is fundamental to very many cellular processes such as gene expression and cell growth, and mutations in some types of these proteins have been found in more than 25% of human cancers. It is therefore important to gain a greater understanding of their function and regulation.

Ian gained his PhD at the University of Sheffield in the UK and moved to the US to work at Harvard, after a spell at the University of Nairobi in Kenya. His research into RAS and other small GTPases began in earnest when he moved to the University of Virginia over 10 years ago. His group has continued to pursue various aspects of nuclear transport, but the majority of the lab now works on the molecular basis for cell polarity establishment.

The Advanced Microscopy Facility that Ian now directs has four confocal microscopes, plus several wide-field and electron microscopes. All of the wide field microscopes are equipped with Openlab for image acquisition and analysis. He uses Openlab on the microscope in his own laboratory as well and has recently added Volocity to his imaging software tools.

Ian writes: “We have used Openlab for our imaging experiments since 1997. It has been invaluable for time-lapse studies, and in particular for FRET assays. I was very excited by the FRET movie that a postdoc in the lab, Quansheng Du, was able to produce using the Openlab FRET module, showing a conformational change in the LGN protein through the cell cycle*. More recently we have been using spinning disk confocal microscopy to track the formation of tight junctions in epithelial cells, and we find that Volocity is ideal for processing the 4D data from the movies. We are also using Volocity to render image stacks from our Zeiss LSM510 confocal microscope, in particular of epithelial cells in which we have knocked down various polarity proteins by RNAi.”

FRET is an important research tool for Ian’s group and some of the members are currently attempting to produce FRET biosensors to detect polarity protein complexes within the living cell. For further details about the FRET work of Ian’s group, please read this Application Note in our Application Library, or visit the Macara group web site for a closer look at their current research projects in this important area of cell biology.

* Du, Q. and Macara, I.G. (2004) Mammalian Pins functions as a conformational switch to couple NuMA and G-proteins. Cell 1119: 1-20.

This image shows cells that were transfected with mRFP1 plus a vector to knock down the adherens junction protein, E-cadherin. After fixation the cells were stained for gp135, an apical membrane marker. The apical surface is normally flat, but in the transfected cells it balloons up into a dome. The cells were imaged using a Zeiss LSM510 with a 100X objective lens (na 1.4). The z-stack was imported into Volocity and rendered in 3D.