Mast Cell-Derived Membrane Proteins

Abstract

An originally developed efficient signal sequence trapping method was used to screen a cDNA library prepared from cultured mast cells derived from mouse bone marrow. As a result, genes encoding type I membrane proteins and comprising a single immunoglobulin domain in the extracellular domain and a motif for transmitting an inhibitory signal into cells were successfully isolated.

1 . An isolated DNA encoding a protein comprising an amino acid sequence in which up to thirty amino acids in the amino acid sequence of SEQ ID NO:4 have been replaced, deleted, inserted, and/or added. 
     
     
         2 . The DNA of  claim 1 , wherein the protein comprises an amino acid sequence in which up to ten amino acids in the amino acid sequence of SEQ ID NO:4 have been replaced, deleted, inserted, and/or added. 
     
     
         3 . The DNA of  claim 1 , wherein the protein comprises an amino acid sequence in which up to five amino acids in the amino acid sequence of SEQ ID NO:4 have been replaced, deleted, inserted, and/or added. 
     
     
         4 . The DNA of  claim 1 , wherein the protein is capable of binding to a second protein selected from the group consisting of DAP10 protein, DAP12 protein, and FcR□ protein. 
     
     
         5 . The DNA of  claim 1 , wherein the amino acid sequence of the protein comprises SEQ ID NO:4. 
     
     
         6 . The DNA of  claim 1 , wherein the amino acid sequence of the protein consists of SEQ ID NO:4. 
     
     
         7 . The DNA of  claim 1 , wherein the DNA comprises the coding region of the nucleotide sequence of SEQ ID NO:3. 
     
     
         8 . A vector comprising the DNA of  claim 1 . 
     
     
         9 . A host cell carrying (i) the DNA of  claim 1  or (ii) a vector comprising the DNA of  claim 1 . 
     
     
         10 . A method for producing a protein comprising an amino acid sequence in which up to thirty amino acids in the amino acid sequence of SEQ ID NO:4 have been replaced, deleted, inserted, and/or added, the method comprising the steps of culturing the host cell of  claim 9 , and recovering the protein from said host cell or the culture supernatant thereof. 
     
     
         11 . An isolated polynucleotide comprising a segment of SEQ ID NO:3 or of the complement of SEQ ID NO:3, the segment being at least 15 nucleotides in length. 
     
     
         12 . An isolated DNA that specifically hybridizes with a probe consisting of the complement of SEQ ID NO:3 under highly stringent conditions. 
     
     
         13 . The DNA of  claim 12 , wherein said highly stringent conditions include a post-hybridization wash in 5×SSC, 0.1% SDS at 65° C. 
     
     
         14 . An isolated DNA that encodes a protein that is 85% or more identical to SEQ ID NO:4. 
     
     
         15 . The DNA of  claim 14 , wherein the DNA encodes a protein that is 95% or more identical to SEQ ID NO:4. 
     
     
         16 . The DNA of  claim 14 , wherein the DNA encodes a protein that is 96% or more identical to SEQ ID NO:4. 
     
     
         17 . The DNA of  claim 14 , wherein the DNA encodes a protein that is 97% or more identical to SEQ ID NO:4. 
     
     
         18 . The DNA of  claim 14  wherein the DNA encodes a protein that is 98% or more identical to SEQ ID NO:4. 
     
     
         19 . The DNA of  claim 14 , wherein the DNA encodes a protein that is 99% or more identical to SEQ ID NO:4. 
     
     
         20 . The DNA of  claim 14 , wherein the protein is capable of binding to a second protein selected from the group consisting of DAP10 protein, DAP12 protein, and FcRγ protein.