Cellular and sub-cellular expression of the GIMAPs
We have been keen to learn more about the intracellular location of GIMAP proteins. Some of them (notably GIMAP1 and GIMAP5) have protein regions which anchor them to membranes. Identifying in which sub-cellular membranes they are to be found could give important clues about their function.
From detailed studies we have drawn the unexpected conclusion that GIMAP5 is a lysosomal protein (Wong et al., 2010). By contrast, we found that GIMAP1 is located in the Golgi system of mouse lymphoid cells.
In the future, we will be interested to look for dynamic changes in the intracellular expression of GIMAP proteins during cellular responses to stimuli such as antigen-receptor activation, apoptosis induction and others (see below for new findings regarding GIMAP6).