SUMMARY PARAGRAPH for MDL2
MDL1 and MDL2 encode members of the ATP-binding Cassette (ABC) transporter family that reside in the mitochondrial inner membrane (1, 2). They are classified as "half-molecule" family members because they are comprised of one transmembrane domain and one nucleotide-binding domain, in contrast to "full-size" family members in which this arrangement is repeated in tandem. Mdl1p and Mdl2p are similar to each other and to other ABC family members, in particular to human TAP1 and TAP2, which form a heterodimer that transports peptides from the cytoplasm into the endoplasmic reticulum (1). Defects in TAP1 and TAP2 are linked to bare lymphocyte syndrome (OMIM) and Wegener-like granulomatosis (OMIM).
Although Mdl2p is very similar to Mdl1p, which exports peptides from mitochondria, the mdl2 null mutation does not affect peptide export. In contrast to mdl1, the mdl null mutation prevents respiratory growth at high temperature (2). Large-scale studies have also detected osmotic stress resistance and oleate sensitivity phenotypes of the mdl2 null mutant (4, 5).
Last updated: 2010-02-09