Mitochondrial solute transporter which transports branched-chain amino acid (BCAA; valine, leucine and isoleucine) into mitochondria in brown adipose tissue (BAT) (By similarity). BAT is involved in BCAA catabolism and actively utilizes BCAA in the mitochondria for thermogenesis (PubMed:31435015). Induction by cold exposure in brown adipose tissues. Belongs to the mitochondrial carrier (TC 2.A.29) family.