Very active and specific thyroid hormone transporter. Stimulates cellular uptake of thyroxine (T4), triiodothyronine (T3), reverse triiodothyronine (rT3) and diidothyronine. Does not transport Leu, Phe, Trp or Tyr (By similarity).
Catalysis of the transfer of monocarboxylic acids from one side of the membrane to the other. A monocarboxylic acid is an organic acid with one COOH group.
Biochem. J. 329 ( Pt 2), 321-328 (1998)[PubMed:9425115]
Measurement of monocarboxylate transport kinetics in a range of cell types has provided strong circumstantial evidence for a family of monocarboxylate transporters (MCTs). Two mammalian MCT isoforms (MCT1 and MCT2) and a chicken isoform (REMP or MCT3) have already been cloned, sequenced and expressed, and another MCT-like sequence (XPCT) has been identified. Here we report the identification of new human MCT homologues in the database of expression sequence tags and the cloning and sequencing of four new full-length MCT-like sequences from human cDNA libraries, which we have denoted MCT3, MCT4, MCT5 and MCT6. Northern blotting revealed a unique tissue distribution for the expression of mRNA for each of the seven putative MCT isoforms (MCT1-MCT6 and XPCT). All sequences were predicted to have 12 transmembrane (TM) helical domains with a large intracellular loop between TM6 and TM7. Multiple sequence alignments showed identities ranging from 20% to 55%, with the greatest conservation in the predicted TM regions and more variation in the C-terminal than the N-terminal region. Searching of additional sequence databases identified candidate MCT homologues from the yeast Saccharomyces cerevisiae, the nematode worm Caenorhabditis elegans and the archaebacterium Sulfolobus solfataricus. Together these sequences constitute a new family of transporters with some strongly conserved sequence motifs, the possible functions of which are discussed.
Enables the active transport of a solute across a membrane by a mechanism whereby two or more species are transported together in the same direction in a tightly coupled process not directly linked to a form of energy other than chemiosmotic energy.
To study the regulation and chromosomal basis of X chromosome inactivation, we have physically characterized the region in Xq13.2 known to contain the X inactivation center (XIC), a locus required in cis for inactivation to occur. Here, we report a novel gene isolated by positional cloning in this region. The gene (previously identified as DXS128E) encodes a predicted 67 kDa protein containing twelve hydrophobic transmembrane domains, characteristic of a family of transporter proteins. Presence of an N-terminal PEST domain, consisting mainly of proline/glutamic acid repeats, suggests that the protein may be rapidly or conditionally degraded. We designate this gene XPCT for X-linked PEST-containing transporter. Expression studies suggest that XPCT is subject to X chromosome inactivation, being expressed only from the active X, despite mapping within 600 kb of the XIST gene which is expressed exclusively from the inactive X. Thus, a chromosomal switch in inactivation pattern occurs between these two genes on the X chromosome.
Biochem. J. 329 ( Pt 2), 321-328 (1998)[PubMed:9425115]
Measurement of monocarboxylate transport kinetics in a range of cell types has provided strong circumstantial evidence for a family of monocarboxylate transporters (MCTs). Two mammalian MCT isoforms (MCT1 and MCT2) and a chicken isoform (REMP or MCT3) have already been cloned, sequenced and expressed, and another MCT-like sequence (XPCT) has been identified. Here we report the identification of new human MCT homologues in the database of expression sequence tags and the cloning and sequencing of four new full-length MCT-like sequences from human cDNA libraries, which we have denoted MCT3, MCT4, MCT5 and MCT6. Northern blotting revealed a unique tissue distribution for the expression of mRNA for each of the seven putative MCT isoforms (MCT1-MCT6 and XPCT). All sequences were predicted to have 12 transmembrane (TM) helical domains with a large intracellular loop between TM6 and TM7. Multiple sequence alignments showed identities ranging from 20% to 55%, with the greatest conservation in the predicted TM regions and more variation in the C-terminal than the N-terminal region. Searching of additional sequence databases identified candidate MCT homologues from the yeast Saccharomyces cerevisiae, the nematode worm Caenorhabditis elegans and the archaebacterium Sulfolobus solfataricus. Together these sequences constitute a new family of transporters with some strongly conserved sequence motifs, the possible functions of which are discussed.
The directed movement of substances (such as macromolecules, small molecules, ions) into, out of or within a cell, or between cells, or within a multicellular organism by means of some agent such as a transporter or pore.
To study the regulation and chromosomal basis of X chromosome inactivation, we have physically characterized the region in Xq13.2 known to contain the X inactivation center (XIC), a locus required in cis for inactivation to occur. Here, we report a novel gene isolated by positional cloning in this region. The gene (previously identified as DXS128E) encodes a predicted 67 kDa protein containing twelve hydrophobic transmembrane domains, characteristic of a family of transporter proteins. Presence of an N-terminal PEST domain, consisting mainly of proline/glutamic acid repeats, suggests that the protein may be rapidly or conditionally degraded. We designate this gene XPCT for X-linked PEST-containing transporter. Expression studies suggest that XPCT is subject to X chromosome inactivation, being expressed only from the active X, despite mapping within 600 kb of the XIST gene which is expressed exclusively from the inactive X. Thus, a chromosomal switch in inactivation pattern occurs between these two genes on the X chromosome.
Protein involved in the transport of solutes across a biological membrane in one direction, which depends on the transport of another solute in the same direction. One molecule can move up an electrochemical gradient because the movement of the other molecule is more favorable. Example: the sodium/glucose co-transport.
Protein involved in the transport of a molecule (metabolite, protein, etc), a ion or an electron across cell membranes, inside the cell or in a tissue fluid.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.
My favorites 
My labels 
Login
