A half-type ABC transporter TAPL is highly conserved between rodent and man, and the human gene is not responsive to interferon-gamma in contrast to TAP1 and TAP2.
TAPL is a half-type ABC transporter with sequence similarity to TAP1 and TAP2 that is transcribed in various rat tissues [Yamaguchi, Y., Kasano, M., Terada, T., Sato, R., and Maeda, M. (1999) FEBS Lett. 457, 231-236]. Primary structures of the human and mouse orthologous counterparts were deduced from cDNAs cloned by means of polymerase chain reaction, and they were compared with that of the rat. The mammalian TAPLs (rat, mouse, and human) are highly conserved, since about 95% of the amino acid residues are identical between rodents and man. Phylogenetic analysis demonstrated that the evolutional rate of TAPL is much slower than those of TAP1 and TAP2, although TAPL could have diverged from an ancestor of TAP1 or that of TAP1 and TAP2. The TAPL-GFP fusion protein transiently expressed in Cos-1 cells was co-localized with PDI, suggesting that TAPL is inserted into endoplasmic reticulum membrane. The conservation of the peptide-binding motifs of TAP proteins in TAPL raises the possibility that the TAPL might be a peptide transporter. The gene for human TAPL is assigned to chromosome 12q24.31-q24.32, while those for TAP1 and TAP2 are located at the MHC locus of chromosome 6p21.!3. Furthermore, the transcription of TAPL gene is not responsive to interferon-gamma, in contrast to TAP1 and TAP2. These results indicate that the gene regulation of TAPL is different from those of TAP1 and TAP2.
Kobayashi
A
A
Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan.
Kasano
M
M
Maeda
T
T
Hori
S
S
Motojima
K
K
Suzuki
M
M
Fujiwara
T
T
Takahashi
E
E
Yabe
T
T
Tanaka
K
K
Kasahara
M
M
Yamaguchi
Y
Y
Maeda
M
M
D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics; D003001:Cloning, Molecular; D017124:Conserved Sequence / Q000235:genetics*; D003593:Cytoplasm / Q000737:chemistry; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007371:Interferon-gamma / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011993:Recombinant Fusion Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
C412573:ABCB9 protein, human; D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; C503300:Abcb9 protein, mouse; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C073119:TAP1 protein, human; C486171:Tap1 protein, mouse; C486172:Tap1 protein, rat; C489516:Tap2 protein, mouse; C489514:Tap2 protein, rat; C071692:TAP2 protein, human; D007371:Interferon-gamma