18221, a novel dual specificity phosphatase and uses thereof

Abstract

The invention provides isolated nucleic acids molecules, designated 18221 nucleic acid molecules, which encode novel dual specificity phosphatase family members. The invention also provides antisense nucleic acid molecules, recombinant expression vectors containing 18221 nucleic acid molecules, host cells into which the expression vectors have been introduced, and nonhuman transgenic animals in which a 18221 gene has been introduced or disrupted. The invention still further provides isolated 18221 proteins, fusion proteins, antigenic peptides and anti-18221 antibodies. Diagnostic methods utilizing compositions of the invention are also provided. The invention also provides methods of modulating the differentiation and proliferation of hematopoietic cells (e.g., erythroid cells) utilizing the compositions of the invention. Accordingly, methods of treating, preventing and/or diagnosing hematopoietic disorders are disclosed.

What is claimed is:  
     
         1 . An isolated nucleic acid molecule selected from the group consisting of: 
 a) a nucleic acid molecule comprising a nucleotide sequence at least 80% identical to the nucleotide sequence of SEQ ID NOs: 1, or 3,or the cDNA insert of the plasmid deposited with the ATCC as Accession Number ______;    b) a nucleic acid molecule comprising a fragment of at least 462 nucleotides of the nucleotide sequence of SEQ ID NO: 1, or 3,or the cDNA insert of the plasmid deposited with the ATCC as Accession Number ______;    c) a nucleic acid molecule encoding a polypeptide comprising the amino acid sequence of SEQ ID NO:2, or the amino acid sequence encoded by the cDNA insert of the plasmid deposited with the ATCC as Accession Number ______;    d) a nucleic acid molecule encoding a fragment of a polypeptide comprising the amino acid sequence of SEQ ID NO:2, or the amino acid sequence encoded by the cDNA insert of the plasmid deposited with the ATCC as Accession Number , wherein the fragment comprises at least 15 contiguous amino acids of SEQ ID NO: 2, or the amino acid sequence encoded by the cDNA insert of the plasmid deposited with the ATCC as Accession Number ______; and    e) a nucleic acid molecule encoding a naturally occurring allelic variant of a polypeptide comprising the amino acid sequence of SEQ ID NO:2, or the amino acid sequence encoded by the cDNA insert of the plasmid deposited with the ATCC as Accession Number ______, wherein the nucleic acid molecule hybridizes to a nucleic acid molecule comprising SEQ ID NO: 1, or 3, or a complement thereof, under stringent conditions.    
     
     
         2 . The isolated nucleic acid molecule of  claim 1 , which is selected from the group consisting of: 
 a) a nucleic acid comprising the nucleotide sequence of SEQ ID NO: 1, or 3,or the cDNA insert of the plasmid deposited with the ATCC as Accession Number ______; and    b) a nucleic acid molecule encoding a polypeptide comprising the amino acid sequence of SEQ ID NO:2, or the amino acid sequence encoded by the cDNA insert of the plasmid deposited with the ATCC as Accession Number ______.    
     
     
         3 . The nucleic acid molecule of  claim 1  further comprising vector nucleic acid sequences.  
     
     
         4 . The nucleic acid molecule of  claim 1  further comprising nucleic acid sequences encoding a heterologous polypeptide.  
     
     
         5 . A host cell which contains the nucleic acid molecule of  claim 1 .  
     
     
         6 . The host cell of  claim 5  which is a mammalian host cell.  
     
     
         7 . A non-human mammalian host cell containing the nucleic acid molecule of  claim 1 .  
     
     
         8 . An isolated polypeptide selected from the group consisting of: 
 a) a polypeptide encoded by a nucleic acid molecule comprising a nucleotide sequence at least 80% identical to a nucleic acid comprising the nucleotide sequence of SEQ ID NO: 1, or 3,the amino acid sequence encoded by the cDNA insert of the plasmid deposited with the ATCC as Accession Number ______;    b) a naturally occurring allelic variant of a polypeptide comprising the amino acid sequence of SEQ ID NO:2, or the amino acid sequence encoded by the CDNA insert of the plasmid deposited with the ATCC as Accession Number ______, wherein the polypeptide is encoded by a nucleic acid molecule that hybridizes to a nucleic acid molecule comprising SEQ ID NO: 1, or 3,or a complement thereof under stringent conditions; and    c) a fragment of a polypeptide comprising the amino acid sequence of SEQ ID NO:2, or the amino acid sequence encoded by the cDNA insert of the plasmid deposited with the ATCC as Accession Number ______, wherein the fragment comprises at least 15 contiguous amino acids of SEQ ID NO:2.    
     
     
         9 . The isolated polypeptide of  claim 8  comprising the amino acid sequence of SEQ ID NO:2.  
     
     
         10 . The polypeptide of  claim 8  further comprising heterologous amino acid sequences.  
     
     
         11 . An antibody which selectively binds to a polypeptide of  claim 8 .  
     
     
         12 . A method for producing a polypeptide selected from the group consisting of: 
 a) a polypeptide comprising the amino acid sequence of SEQ ID NO:2, or the amino acid sequence encoded by the cDNA insert of the plasmid deposited with the ATCC as Accession Number ______;    b) a polypeptide comprising a fragment of the amino acid sequence of SEQ ID NO:2, or the amino acid sequence encoded by the cDNA insert of the plasmid deposited with the ATCC as Accession Number ______, wherein the fragment comprises at least 15 contiguous amino acids of SEQ ID NO:2, or the amino acid sequence encoded by the cDNA insert of the plasmid deposited with the ATCC as Accession Number ______; and    c) a naturally occurring allelic variant of a polypeptide comprising the amino acid sequence of SEQ ID NO:2, or the amino acid sequence encoded by the cDNA insert of the plasmid deposited with the ATCC as Accession Number ______, wherein the polypeptide is encoded by a nucleic acid molecule which hybridizes to a nucleic acid molecule comprising SEQ ID NOs: 1, or 3, or a complement thereof under stringent conditions;    comprising culturing the host cell of  claim 5  under conditions in which the nucleic acid molecule is expressed.    
     
     
         13 . A method for detecting the presence of a polypeptide of  claim 8  in a sample, comprising: 
 a) contacting the sample with a compound which selectively binds to a polypeptide of claim  8 ; and  
 b) determining whether the compound binds to the polypeptide in the sample.  
 
     
     
         14 . The method of  claim 13 , wherein the compound which binds to the polypeptide is an antibody.  
     
     
         15 . A kit comprising a compound which selectively binds to a polypeptide of  claim 8  and instructions for use.  
     
     
         16 . A method for detecting the presence of a nucleic acid molecule of  claim 1  in a sample, comprising the steps of: 
 a) contacting the sample with a nucleic acid probe or primer which selectively hybridizes to the nucleic acid molecule; and  
 b) determining whether the nucleic acid probe or primer binds to a nucleic acid molecule in the sample.  
 
     
     
         17 . The method of  claim 16 , wherein the sample comprises mRNA molecules and is contacted with a nucleic acid probe.  
     
     
         18 . A kit comprising a compound which selectively hybridizes to a nucleic acid molecule of  claim 1  and instructions for use.  
     
     
         19 . A method for identifying a compound which binds to a polypeptide of  claim 8  comprising the steps of: 
 a) contacting a polypeptide, or a cell expressing a polypeptide of  claim 8  with a test compound; and  
 b) determining whether the polypeptide binds to the test compound.  
 
     
     
         20 . The method of  claim 19 , wherein the binding of the test compound to the polypeptide is detected by a method selected from the group consisting of: 
 a) detection of binding by direct detecting of test compound/polypeptide binding;    b) detection of binding using a competition binding assay; and    c) detection of binding using an assay for tyrosine phosphatase-mediated signal transduction.    
     
     
         21 . A method for modulating the activity of a polypeptide of  claim 8  comprising contacting a polypeptide or a cell expressing a polypeptide of  claim 8  with a compound which binds to the polypeptide in a sufficient concentration to modulate the activity of the polypeptide.  
     
     
         22 . A method for identifying a compound which modulates the activity of a polypeptide of  claim 8 , comprising: 
 a) contacting a polypeptide of  claim 8  with a test compound; and    b) determining the effect of the test compound on the activity of the polypeptide to thereby identify a compound which modulates the activity of the polypeptide.    
     
     
         23 . The method of  claim 22 , wherein the activity is protein phosphatase activity.  
     
     
         24 . A method for modulating hematopoiesis, comprising contacting a hematopoietic cell with an agent that modulates the activity or expression of a polypeptide of  claim 8 , thereby modulating the proliferation, differentiation or survival of the hematopoiesis cell.  
     
     
         25 . The method of  claim 24 , wherein the hematopoitic cell is an erythroid progenitor or differentiated cell.  
     
     
         26 . The method of  claim 24 , wherein the contacting step is effected in vivo in a subject.  
     
     
         27 . The method of  claim 26 , wherein the subject is a human.  
     
     
         28 . The method of  claim 24 , wherein the agent is a peptide, a small molecule, an antibody, or any combination thereof.  
     
     
         29 . A method of modulating hematopoiesis, comprising contacting a hematopoietic cell with an agent that modulates the activity or expression of a nucleic acid of  claim 1 , thereby modulating the proliferation, differentiation or survival of the hematopoietic cell.  
     
     
         30 . The method of  claim 29 , wherein the agent is an antisense, a ribozyme, a triple helix molecule, or any combination thereof.  
     
     
         31 . A method of treating or preventing a hematopoietic disorder, in a subject, comprising administering to the subject an effective amount of a compound that modulates the activity or expression of a polypeptide of  claim 8 , such that the hematopoietic disorder is ameliorated or prevented.  
     
     
         32 . A method for evaluating the efficacy of a treatment of a hematopoietic disorder, in a subject, comprising: 
 treating a subject with a protocol under evaluation;    assessing the expression level of a nucleic acid of  claim 1 ,    wherein a change in the expression level of the nucleic acid after the treatment, relative to the level before the treatment, is indicative of the efficacy of the treatment of the hematopoietic disorder.    
     
     
         33 . A method for evaluating the efficacy of a treatment of a hematopoietic disorder, in a subject, comprising: 
 treating a subject with a protocol under evaluation;    assessing the expression level of a polypeptide of  claim 8 ,    wherein a change in the expression level of the polypeptide after the treatment, relative to the level before the treatment, is indicative of the efficacy of the treatment of the hematopoietic disorder.    
     
     
         34 . The method of  claim 32 , further comprising treating the subject with erythropoietin prior to assessing expression levels.  
     
     
         35 . The method of  claim 32 , wherein the subject is a patient having an erythroid-associated disorder.  
     
     
         36 . A method of diagnosing, or staging, a hematopoietic disorder, in a subject, comprising: 
 evaluating the expression or activity of a nucleic acid of  claim 1 , such that, a difference in the level of the nucleic acid or the polypeptide relative to a normal subject or a cohort of normal subjects is indicative of the hematopoietic disorder.    
     
     
         37 . A method of diagnosing, or staging, a hematopoietic disorder, in a subject, comprising: 
 evaluating the expression or activity of a polypeptide of  claim 8 , such that, a difference in the level of the nucleic acid or the polypeptide relative to a normal subject or a cohort of normal subjects is indicative of the hematopoietic disorder.