NAR2 is a family of plant proteins with a C-terminal transmembrane region that is an essential accessory for high-affinity nitrate uptake. This family works together with NRT2, a 12xTM family of proteins that is part of family MFS_1, pfam07690. NAR2 is also involved in the repression of lateral root initiation in response to high ratios of sucrose to nitrogen in the medium. Therefore the two component-system of NAR2 and NRT2 itself is likely to be involved in the signalling pathway that integrates nutritional cues for the regulation of lateral root architecture. The functional unit of the high-affinity nitrate influx complex is likely to be a tetramer, in Arabidopsis, made up of two subunits each of NRT2.1 and NAR2.1. This entry corresponds to an immunoglobulin-like domain.
Jiyao W et al.(2023). "The conserved domain database in 2023.",