COMPOSITIONS AND METHODS COMPRISING ASPARTYL-tRNA SYNTHETASES HAVING NON-CANONICAL BIOLOGICAL ACTIVITIES

Abstract

Isolated aspartyl-tRNA synthetase polypeptides and polynucleotides having non-canonical biological activities are provided, as well as compositions and methods related thereto.

1 . An isolated aspartyl-tRNA synthetase (AspRS) polypeptide having a non-canonical biological activity, or an active variant thereof. 
     
     
         2 . The isolated aspartyl-tRNA synthetase polypeptide of  claim 1  where the non-canonical biological activity is selected from the group consisting of modulation of cell proliferation, modulation of apoptosis, modulation of inflammation, modulation of cell differentiation, modulation of angiogenesis, modulation of cell binding, modulation of Akt-mediated cell signaling, modulation of cellular metabolism, modulation of cytokine production or activity, and modulation of toll-like receptor signaling. 
     
     
         3 . The isolated aspartyl-tRNA synthetase polypeptide of  claim 1  where the polypeptide is a fragment of the full length human aspartyl-tRNA synthetase sequence set forth in SEQ ID NO: 1. 
     
     
         4 . The isolated aspartyl-tRNA synthetase polypeptide of  claim 1  where the active variant thereof is a polypeptide having at least 80% or 90% identity along its length to a human aspartyl-tRNA synthetase sequence set forth in SEQ ID NO: 1. 
     
     
         5 . The isolated aspartyl-tRNA synthetase polypeptide of  claim 1  where the polypeptide consists essentially of amino acid residues 1-31, 1-154, 1-171, or 1-174 of
 SEQ ID NO: 1, or an active fragment or variant thereof.   
     
     
         6 . A fusion polypeptide comprising a polypeptide of  claim 1  and a heterologous fusion partner. 
     
     
         7 . A dimeric or multimeric complex comprising at least one isolated aspartyl-tRNA synthetase polypeptide of  claim 1 . 
     
     
         8 . An isolated polynucleotide encoding a polypeptide of  claim 1 , or a complement thereof. 
     
     
         9 . An expression vector comprising an isolated polynucleotide of  claim 8 . 
     
     
         10 . A host cell comprising an expression vector of  claim 9 . 
     
     
         11 . An oligonucleotide that specifically hybridizes to a polynucleotide of  claim 8 . 
     
     
         12 . The oligonucleotide of  claim 11 , selected from a primer, a probe, and an antisense oligonucleotide. 
     
     
         13 . A binding agent that exhibits binding specificity for an isolated AspRS polypeptide of  claim 1 , a cellular binding partner of the AspRS polypeptide, or both. 
     
     
         14 . The binding agent of  claim 13 , selected from an antibody, an antigen-binding fragment thereof, a peptide, peptide mimetic, a small molecule, and an aptamer. 
     
     
         15 . The binding agent of  claim 13 , wherein the binding agent antagonizes a non-canonical activity of the AspRS polypeptide. 
     
     
         16 . The binding agent of  claim 13 , wherein the binding agent agonizes a non-canonical activity of the AspRS polypeptide. 
     
     
         17 . A method of determining presence or levels of an aspartyl-tRNA synthetase (AspRS) polypeptide in a sample, comprising:
 contacting the sample with one or binding agents that specifically bind to an AspRS polypeptide according to  claim 1 , detecting the presence or absence of the binding agent, and thereby determining the presence or levels of the AspRS polypeptide: or   introducing the sample into a detector that is capable of specifically identifying an AspRS polypeptide according to  claim 1 , and thereby determining the presence or levels of the AspRS polypeptide.   
     
     
         18 . (canceled) 
     
     
         19 . The method of  claim 17 , wherein the molecular detector is a mass spectrometer (MS). 
     
     
         20 . The method of  claim 17 , comprising comparing the presence or levels of the AspRS protein fragment to a control sample or a predetermined value. 
     
     
         21 . The method of  claim 20 , comprising characterizing the state of the sample to distinguish it from the control. 
     
     
         22 . The method of  claim 21 , wherein the sample and control comprise a cell or tissue, and the method comprises distinguishing between cells or tissues of different species, cells of different tissues or organs, cells at different cellular developmental states, cells at different cellular differentiation states, or healthy and diseased cells. 
     
     
         23 . A method of identifying a compound that specifically binds to an aspartyl-tRNA synthetase (AspRS) polypeptide according to  claim 1 , or one or more of its cellular binding partners, comprising a) combining the AspRS polypeptide or its cellular binding partner or both with at least one test compound under suitable conditions, and b) detecting binding of the AspRS polypeptide or its cellular binding partner or both to the test compound, thereby identifying a compound that specifically binds to the AspRS polypeptide or its cellular binding partner or both. 
     
     
         24 . The method of  claim 23 , wherein the test compound is a polypeptide or peptide, an antibody or antigen-binding fragment thereof, a peptide mimetic, or a small molecule. 
     
     
         25 . The method of  claim 23 , wherein the test compound agonizes a non-canonical biological activity of the AspRS polypeptide or its cellular binding partner. 
     
     
         26 . The method of  claim 23 , wherein the test compound antagonizes a non-canonical biological activity of the AspRS polypeptide or its cellular binding partner. 
     
     
         27 . A compound identified by the method of  claim 23 . 
     
     
         28 . A composition comprising a physiologically acceptable carrier and at least one component selected from the group consisting of: (i) an isolated aspartyl-tRNA synthetase (AspRS) polypeptide having a non-canonical biological activity, or an active, variant thereof; (ii) a fusion protein comprising an AspRS polypeptide of (i); (iii) a dimeric or multimeric complex comprising an AspRS polypeptide of (i); (iv) an isolated polynucleotide that encodes an AspRS polypeptide of (i); (v) an expression vector comprising a polynucleotide of (iv); (vi) an oligonucleotide that specifically hybridizes to a polynucleotide of (iv); (vii) a binding agent that exhibits binding specificity for an AspRS polypeptide of (i); and (viii) a compound according to  claim 27 . 
     
     
         29 . A method for modulating a cellular activity comprising contacting a cell or tissue with a composition of  claim 28 . 
     
     
         30 . The method of  claim 29 , wherein the cellular activity is selected from the group consisting of cell migration, cell proliferation, apoptosis, inflammation, cell differentiation, angiogenesis, modulation of cell binding, Akt-mediated cell signaling, cellular metabolism, cytokine production, and toll-like receptor signaling. 
     
     
         31 . The method of  claim 30 , wherein the cellular activity is cytokine production. 
     
     
         32 . The method of  claim 31 , wherein the cytokine is any one or more of IL1-β, IL-6, IL-8, IL-10, IL-12p40, MIP1-α, MIP-1β, GRO-α, MCP-1, or IL-1ra. 
     
     
         33 . The method of  claim 30 , wherein the cellular activity is toll-like receptor (TLR) signaling. 
     
     
         34 . The method of  claim 33 , wherein the TLR is TLR2, TLR4, or both. 
     
     
         35 . The method of  claim 34 , wherein the method is a method of stimulating an innate immune response. 
     
     
         36 . The method of  claim 29 , wherein the cell is in a subject. 
     
     
         37 . A method for treating a condition comprising administering to a subject in need thereof a composition of  claim 29 , wherein the condition is selected from the group consisting of inflammatory diseases, autoimmune diseases, neoplastic diseases, metabolic diseases, neurological diseases, infections, cardiovascular diseases, and diseases associated with abnormal angiogenesis.