The projection of data (or, a grid) that is displayed on the current axes can be set with the command:
setm(gca,'MapProjection',projection_name)
However, the Mapping Toolbox 2.2 does not provide a function for converting the data itself between projections. Re-projecting the grid itself would require some careful programming and would be best done in conjunction with the Image Processing Toolbox.
As a workaround, the MODIS Reprojection Tool can be used to re-sample the data:
<https://lpdaac.usgs.gov/lpdaac/tools/modis_reprojection_tool>
