Neutral amino acid transporter and gene thereof

Abstract

The present invention relates to an amino acid transporter protein having the ability to mediate the transport of amino acids into a cell, a gene encoding the protein, an antibody having a reactivity with the protein, a cell which produces the antibody, related kits and methods.

1 . Protein which is a cell surface protein having an ability of mediating the transport of amino acid into cell and having an ability of mediating the incorporation of at least one amino acid selected from a group consisting of leucine (Leu), isoleucine (Ile), phenylalanine (Phe), methionine (Met), tyrosine (Tyr), tryptophan (Trp), valine (Val) and histidine (His) into the cell in an Na + -independent manner. 
     
     
         2 . The protein according to  claim 1 , wherein, when it coexists with a 4F2hc protein classified under a type II membrane glycoprotein or a part thereof, it has an ability of transportation of neutral amino acid and substances similar thereto. 
     
     
         3 . The protein according to  claim 2 , wherein the 4F2hc protein classified under a type II membrane glycoprotein is a protein having an amino acid sequence mentioned in SEQ ID NO:6 or NO:8 or an amino acid sequence where a part of amino acids thereof is deleted, substituted or added. 
     
     
         4 . The protein according to any of  claims 1  to  3 , wherein it is a protein derived from human being or rat. 
     
     
         5 . The protein according to any of  claims 1  to  4 , wherein it has an amino acid sequence of any of the following (1) and (2).
 (1): an amino acid sequence mentioned in SEQ ID NO: 2 or NO:4 
 (2): an amino acid sequence mentioned in SEQ ID NO:2 or NO:4 where one or more amino acid(s) is/are deleted, substituted or added. 
 
     
     
         6 . A polypeptide containing a partial amino acid sequence in the amino acid sequence mentioned in SEQ ID NO:2 or NO:4 and having an antigenicity. 
     
     
         7 . DNA coding for any of the protein mentioned in any of  claims 1  to  5 . 
     
     
         8 . The DNA according to  claim 7 , wherein it is a DNA derived from human being or rat. 
     
     
         9 . DNA coding for a cell surface protein which hybridizes under a stringent condition to the DNA having a base sequence of from 66th to 1586th bases mentioned in SEQ ID NO:1 or having a base sequence of from 64th to 1599th bases mentioned in SEQ ID NO:3 and has an ability of mediating the incorporation of at least one kind of amino acid into cell. 
     
     
         10 . The DNA according to  claim 9 , wherein it codes for a cell surface protein where incorporation of amino acid into the cell is mediated by the coexistence of a 4F2hc protein classified under the type II membrane glycoprotein or a part thereof. 
     
     
         11 . The DNA according to  claim 10 , wherein the 4F2hc protein classified under the type II membrane glycoprotein has an amino acid sequence mentioned in SEQ ID NO:6 or NO:8 or an amino acid sequence where a part of amino acids is deleted, substituted or added. 
     
     
         12 . RNA which is able to be derived from the DNA mentioned in  claims 7  to  11 . 
     
     
         13 . The RNA according to  claim 12 , wherein it is an RNA having a base sequence mentioned in SEQ ID NO:26 or NO:27. 
     
     
         14 . An expression vector containing the DNA mentioned in any of  claims 7  to  11 . 
     
     
         15 . A transformant cell which is transformed by the expression vector mentioned in  claim 14 . 
     
     
         16 . The transformant cell according to  claim 14  or  15 , wherein the transformant cell is further transformed by a DNA containing a base sequence comprising a base sequence of from 110th to 1696th bases in the base sequence mentioned in SEQ ID NO:5 and any one of nonsense base sequence represented by TAG, TGA or TAA adjacent to the 1696th base. 
     
     
         17 . The transformant cell according to any of  claims 14  to  16 , wherein the transformant cell is further transformed by a DNA coding for a reporter protein. 
     
     
         18 . A cell which is derived from human being into which the RNA mentioned in  claim 12  or  13  is introduced. 
     
     
         19 . The cell according to  claim 18 , wherein the cell is an oocyte of  Xenopus laevis.    
     
     
         20 . An antiserum or a polyclonal antibody having a reactivity with the protein mentioned in any of  claims 1  to  5  or to the polypeptide mentioned in  claim 6 . 
     
     
         21 . A monoclonal antibody having a reactivity with the protein mentioned in any of  claims 1  to  5  or to the polypeptide mentioned in  claim 6  or a part of the monoclonal antibody. 
     
     
         22 . The monoclonal antibody or a part of the monoclonal antibody according to  claim 21 , wherein the monoclonal antibody is a recombined chimera monoclonal antibody comprising a variable region of immunoglobulin derived from mammals except human being and a constant region of immunoglobulin derived from human being. 
     
     
         23 . The monoclonal antibody or a part of the monoclonal antibody according to  claim 21 , wherein the monoclonal antibody is a recombined human type monoclonal antibody comprising all or a part of a complementarity-determining region of a hypervariable region of immunoglobulin derived from mammals except human being, a frame region of a hypervariable region of immunoglobulin derived from human being and a constant region of immunoglobulin derived from human being. 
     
     
         24 . The monoclonal antibody or a part of the monoclonal antibody mentioned in any of  claims 21  to  23 , wherein the monoclonal antibody is a human monoclonal antibody. 
     
     
         25 . A cell which produces the monoclonal antibody mentioned in any of  claims 21  to  24 . 
     
     
         26 . The cell according to  claim 25 , wherein the cell is a fused cell prepared by a fusion of a B cell derived from non-human mammals having an ability of producing the monoclonal antibody with a myeloma cell derived from mammals. 
     
     
         27 . The cell according to  claim 25 , wherein the cell is a genetically recombined cell transformed by introduction of DNA coding for heavy chain of the monoclonal antibody, DNA coding for light chain thereof or both of the DNA into the cell. 
     
     
         28 . A pharmaceutical composition containing the DNA mentioned in any of  claims 7  to  11  and a pharmaceutically acceptable carrier. 
     
     
         29 . The pharmaceutical composition according to  claim 28 , wherein the pharmaceutical composition is used for suppressing the growth of the tumor cells. 
     
     
         30 . A pharmaceutical composition containing the RNA mentioned in  claim 12  or  13  and a pharmaceutically acceptable carrier. 
     
     
         31 . The pharmaceutical composition according to  claim 30 , wherein the pharmaceutical composition is used for suppressing the growth of the tumor cells. 
     
     
         32 . A pharmaceutical composition containing the antiserum or the polyclonal antibody mentioned in  claim 20  and a pharmaceutically acceptable carrier. 
     
     
         33 . The pharmaceutical composition according to  claim 32 , wherein the pharmaceutical composition is used for suppressing the growth of the tumor cells. 
     
     
         34 . A pharmaceutical composition containing the monoclonal antibody mentioned in any of  claims 21  to  24  or a part of the monoclonal antibody and a pharmaceutically acceptable carrier. 
     
     
         35 . The pharmaceutical composition according to  claim 34 , wherein the pharmaceutical composition is used for suppressing the growth of the tumor cells. 
     
     
         36 . A labeled monoclonal antibody in which the monoclonal antibody mentioned in any of  claims 21  to  24  is labeled with a labeling substance which is able to give a detectable signal either solely or by the reaction with other substance. 
     
     
         37 . The labeled monoclonal antibody according to  claim 36 , wherein the labeling substance is enzyme, fluorescent substance, chemiluminescent substance, biotin, avidin or radioisotope. 
     
     
         38 . A kit which is to detect the protein having the amino acid sequence mentioned in SEQ ID NO:2 or a fragment where the kit comprises the labeled monoclonal antibody mentioned in  claim 36  or  37 . 
     
     
         39 . A method for the examination whether protein is expressed in a sample or for the examination of the expressed amount, characterized in that, the method comprises:
 (1) a step where the sample is contacted to the labeled monoclonal antibody mentioned in  claims 36  or  37  and   (2) a step where the amount of the labeled monoclonal antibody bonded to the sample is measured by detecting fluorescence, chemiluminescence or radioactivity depending upon the type of the labeling substance bonded to the labeled monoclonal antibody.   
     
     
         40 . The method according to  claim 39 , wherein the sample is tumor cell, tumor tissue, tumor-having organ or a part thereof. 
     
     
         41 . A labeled DNA in which the DNA mentioned in any of  claims 7  to  11  or a fragment thereof is labeled with enzyme, fluorescent substance, chemiluminescent substance, biotin, avidin or radioisotope. 
     
     
         42 . A radiolabeled RNA in which the RNA mentioned in  claim 12  or  13  or a fragment thereof is labeled with a radioisotope. 
     
     
         43 . A kit for detecting the gene coding for the protein mentioned in any of  claims 1  to  5 , characterized in that, the kit comprises the labeled DNA mentioned in  claim 41  or the radioactive RNA mentioned in  claim 42 . 
     
     
         44 . A method for detecting the action as a substrate of a test substance to the ability for transporting the neutral amino acids of the protein using the protein mentioned in any of  claims 1  to  5 . 
     
     
         45 . The method according to  claim 44 , wherein the cell transformed by the DNA mentioned in any of  claims 7  to  11  is used. 
     
     
         46 . The method according to  claim 44 , wherein an oocyte of  Xenopus laevis  is used. 
     
     
         47 . The method according to any of  claims 44  to  46 , wherein the test substance is a substance other than an amino acid. 
     
     
         48 . A method for screening the test substance having an action of suppressing the ability for transport of neutral amino acid and similar substance thereto of the protein using the protein mentioned in any of  claims 1  to  5 . 
     
     
         49 . The method according to  claim 48 , wherein the cell which is transformed by the DNA mentioned in any of  claims 7  to  11  is used. 
     
     
         50 . The method according to  claim 49 , wherein an oocyte of  Xenopus laevis  is used. 
     
     
         51 . A method for the identification of a substance having an ability of inhibiting the transcription of the DNA mentioned in any of  claims 7  to  11  to mRNA or the expression of the protein mentioned in any of  claims 1  to  5 . 
     
     
         52 . A substance which is detected, screened or identified by a method mentioned in any of  claims 44  to  51 . 
     
     
         53 . The substance according to  claim 52 , wherein the substance is a substance having an ability of inhibiting the growth of tumor cell. 
     
     
         54 . A transgenic mouse having an extrinsic gene, characterized in that, a DNA coding for a protein having an amino acid sequence mentioned in SEQ ID NO:2 or NO:4 is incorporated on an intrinsic gene of the mouse whereupon the mouse has a cell expressing the protein in its body. 
     
     
         55 . The transgenic mouse according to  claim 54 , wherein the DNA is a DNA which contains a base sequence comprising a base sequence of from 66th to 1586th bases in the base sequence mentioned in SEQ ID NO:1 and any one nonsense base sequence represented by TAG, TGA or TAA adjacent to the 1586th base or a base sequence comprising a base sequence of from 64th to 1599th bases in the base sequence mentioned in SEQ ID NO:3 and any one nonsense base sequence represented by TAG, TGA or TAA adjacent to the 1599th base.