OCT-3 gene encoding transporter-like molecules

Details OCT-3 gene encoding transporter-like molecules OCT-3 gene encoding transporter-like molecules

1997-11-06

2001-08-21

Horlick, Kenneth R. (Department: 1653)

Chemistry: molecular biology and microbiology

Measuring or testing process involving enzymes or...

Involving nucleic acid

C435S091100, C435S091200, C536S023100, C536S023500, C536S024300, C536S024310, C536S024320

Reexamination Certificate

active

06277565

ABSTRACT:

BACKGROUND OF THE INVENTION
The field of the invention is cellular transporter molecules.
In the course of performing their normal physiological functions, many types of cells, including bacterial cells and those in specialized mammalian tissues such as the liver and kidney, transport a variety of organic molecules across their cell membranes. For example, cells in the proximal tubule of the kidney transport glucose, amino acids, and uric acid across their membranes, and work to eliminate various drugs and toxic substances from the body. All of these molecules are transported across the cell membranes by specialized cellular transporters.
Recently, genes encoding several putative transporters have been identified. These molecules include OCT-1 (
o
rganic
c
ation
t
ransporter; Grundemann et al.,
Nature
372:549-552, 1994), OCT-2 (Okuda et al.,
Biochem. Biophys. Res. Comm
. 224:500-507, 1996), NLT (
n
ovel
l
iver-specific
t
ransporter; Simonson et al.,
J. Cell Sci
. 107:1067-1072, 1994), and NKT (
n
ovel
k
idney-specific
t
ransporter; Lopez-Nieto et al.,
J. Biol. Chem
. 272:6471-6478, 1997). While the sequences of these transporters are not highly conserved (at the amino acid level, OCT-1 and NLT are only 30% and 35% identical to NKT, respectively), they do exhibit similar transmembrane (TM) domain hydropathy profiles.
SUMMARY OF THE INVENTION
The invention described herein relates to the discovery and characterization of oct-3, a gene encoding a protein that transports molecules across the plasma membranes of biological cells. OCT-3 is highly expressed in the neuronal cells of the brain. Accordingly, altering the expression or activity of OCT-3 (e.g., with small molecules, antisense molecules, or neutralizing antibodies) can alter the concentration of molecules (such as neurotransmitters) that are present within the cell or in the extracellular spaces around the cell (i.e., on either side of the plasma membrane). Altering the concentrations of these molecules in patients afflicted with certain conditions, including neurodegenerative diseases, behavioral disorders, and eating or sleep disorders, can provide relief from the symptoms associated with these conditions.
More specifically, the invention features an isolated nucleic acid molecule (i.e., a nucleic acid molecule that is separated from the 5′ and 3′ coding sequences with which it is immediately contiguous in the naturally occurring genome of an organism) that encodes an OCT-3 polypeptide. As used herein, an OCT-3 polypeptide is a polypeptide that: (1) is expressed in the plasma membrane of a biological cell (e.g., a cell in the kidney, liver, or brain), (2) contains TM domains, and (3) when functioning normally, transports organic molecules across the plasma membrane. Preferably, the OCT-3 polypeptide has at least 6 transmembrane domains (e.g., 6, 8, or 10 TM domains), and more preferably, has at least 12 TM domains. The OCT-3 polypeptide can be a mammalian polypeptide, i.e., a polypeptide normally expressed by the cells of a mammal, such as a human. In the event the OCT-3 polypeptide is human, it can have the sequence shown in SEQ ID NO:2 or SEQ ID NO:4, or it can be encoded by nucleic acid molecules having the sequence shown in SEQ ID NO:1 or SEQ ID NO:3. However, the invention is not limited to nucleic acid molecules and polypeptides that are identical to those SEQ ID Nos. For example, the invention includes nucleic acid molecules which encode splice variants, allelic variants or mutant forms of OCT-3 as well as the proteins encoded by such nucleic acid molecules. Also within the invention are nucleic acid molecules that hybridize under stringent conditions to a nucleic acid molecule having the sequence of SEQ ID NO:1 or SEQ ID NO:3. As described further below, molecules that are substantially identical to SEQ ID Nos. 1-4 are also encompassed.
The term “substantially pure” as used herein in reference to a given compound (e.g., an OCT-3 polypeptide) means that the compound is substantially free from other compounds, such as those in cellular material, viral material, or culture medium, with which the compound may have been associated (e.g., in the course of production by recombinant DNA techniques or before purification from a natural biological source). When chemically synthesized, a compound of the invention is substantially pure when it is substantially free from the chemical compounds used in the process of its synthesis. Polypeptides or other compounds of interest are substantially free from other compounds when they are within preparations that are at least 60% by weight (dry weight) the compound of interest. Preferably, the preparation is at least 75%, more preferably at least 90%, and most preferably at least 99%, by weight the compound of interest. Purity can be measured by any appropriate standard method, for example, by column chromatography, polyacrylamide gel electrophoresis, or HPLC analysis.
Where a particular polypeptide or nucleic acid molecule is said to have a specific percent identity to a reference polypeptide or nucleic acid molecule of a defined length, the percent identity is relative to the reference polypeptide or nucleic acid molecule. Thus, a peptide that is 50% identical to a reference polypeptide that is 100 amino acids long can be a 50 amino acid polypeptide that is completely identical to a 50 amino acid long portion of the reference polypeptide. It might also be a 100 amino acid long polypeptide which is 50% identical to the reference polypeptide over its entire length. Of course, many other polypeptides will meet the same criteria. The same rule applies for nucleic acid molecules.
For polypeptides, the length of the reference polypeptide sequence will generally be at least 16 amino acids, preferably at least 20 amino acids, more preferably at least 25 amino acids, and most preferably 35 amino acids, 50 amino acids, or 100 amino acids. For nucleic acids, the length of the reference nucleic acid sequence will generally be at least 50 nucleotides, preferably at least 60 nucleotides, more preferably at least 75 nucleotides, and most preferably at least 100 nucleotides (e.g., 150, 200, 250, or 300 nucleotides).
In the case of polypeptide sequences that are less than 100% identical to a reference sequence, the non-identical positions are preferably, but not necessarily, conservative substitutions for the reference sequence. Conservative substitutions typically include substitutions within the following groups: glycine and alanine; valine, isoleucine, and leucine; aspartic acid and glutamic acid; asparagine and glutamine; serine and threonine; lysine and arginine; and phenylalanine and tyrosine.
Sequence identity can be measured using sequence analysis software (e.g., the Sequence Analysis Software Package of the Genetics Computer Group, University of Wisconsin Biotechnology Center, 1710 University Avenue, Madison, Wis. 53705), with the default parameters as specified therein.
The invention also features a host cell that includes an isolated nucleic acid molecule encoding OCT-3 (either alone or in conjunction with a heterologous polypeptide, such as a detectable marker), or a nucleic acid vector that contains a sequence encoding OCT-3 (again, with or without a heterologous polypeptide). The vector can be an expression vector, and can include a regulatory element.
An antibody that specifically binds an OCT-3 polypeptide is also within the scope of the present invention and is useful, for example, to detect OCT-3 in a biological sample, or to alter the activity of OCT-3. For example, OCT-3 can be detected in a biological sample by contacting the sample with an antibody that specifically binds OCT-3 under conditions that allow the formation of an OCT-3-antibody complex and detecting the complex, if present, as an indication of the presence of OCT-3 in the sample. The use of an antibody in a treatment regime, where it can alter the activity of OCT-3, is discussed further below.
An antibody of the invention can be a monoclonal, polyclonal, or engineered antibody that specific

Affiliated with

Also associated with

Rating

OCT-3 gene encoding transporter-like molecules does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with OCT-3 gene encoding transporter-like molecules, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and OCT-3 gene encoding transporter-like molecules will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2460511