STAR1-STAR2 transporter transports UDP-glucose. STAR1 encodes a nucleotide binding domain, while STAR2 encodes a transmembrane domain, of a bacterial-type ATP binding cassette (ABC) transporter. Both STAR1 and STAR2 are expressed mainly in the roots and are specifically induced by Al exposure. STAR1 and STAR2 form a complex that functions as an ABC transporter, which is required for detoxification of Al in rice (Huang et al., 2009). Localization of STAR1 and STAR2 proteins is unclear (Huang et al., 2009).
