Novel human lipase proteins, nucleic acids encoding them, and uses of both of these

Abstract

The invention provides isolated nucleic acids encoding human lipase proteins and fragments, derivatives, and variants thereof. These nucleic acids and proteins are useful for diagnosis, prevention, and therapy of a number of human and other animal disorders associated, for example, with aberrant lipid metabolism or aberrant pancreatic activity. The invention also provides antisense nucleic acid molecules, expression vectors containing the nucleic acid molecules of the invention, host cells into which the expression vectors have been introduced, and non-human transgenic animals in which a nucleic acid molecule of the invention has been introduced or disrupted. The invention still further provides isolated polypeptides, fusion polypeptides, antigenic peptides, and antibodies. Diagnostic, prognostic, screening, and therapeutic methods involving use of compositions of the invention are also provided. The nucleic acids and polypeptides of the present invention are useful as modulating agents in regulating a variety of cellular processes relating to mono-, di-, and triglyceride metabolism and pancreatic function.

What is claimed is:  
     
         1 . An isolated nucleic acid molecule selected from the group consisting of: 
 a) a nucleic acid molecule having a nucleotide sequence which is at least 40% identical to the nucleotide sequence of one of SEQ ID NOs: 1 and 2, or a complement thereof;    b) a nucleic acid molecule comprising a portion having a nucleotide sequence identical to at least 56 consecutive nucleotide residues of one of SEQ ID NOs: 1 and 2, or a complement thereof;    c) a nucleic acid molecule which encodes a polypeptide having the amino acid sequence of SEQ ID NO: 3, or a complement thereof;    d) a nucleic acid molecule which encodes a fragment of a polypeptide having the amino acid sequence of SEQ ID NO: 3, wherein the fragment comprises at least 17 consecutive amino acid residues of the polypeptide; and    e) a nucleic acid molecule which encodes a naturally-occurring allelic variant of a polypeptide having the amino acid sequence of SEQ ID NO: 3, wherein the nucleic acid molecule hybridizes under stringent conditions with a nucleic acid molecule having of the nucleotide sequence of one of SEQ ID NOs: 1 and 2, or a complement thereof.    
     
     
         2 . The isolated nucleic acid molecule of  claim 1 , which is selected from the group consisting of: 
 a) a nucleic acid having the nucleotide sequence of one of SEQ ID NOs: 1 and 2, or a complement thereof; and    b) a nucleic acid molecule which encodes a polypeptide having the amino acid sequence of SEQ ID NO: 3, or a complement thereof.    
     
     
         3 . The nucleic acid molecule of  claim 1 , further comprising a vector nucleic acid sequence.  
     
     
         4 . The nucleic acid molecule of  claim 1  further comprising a portion encoding a heterologous polypeptide.  
     
     
         5 . A host cell which contains the nucleic acid molecule of  claim 1 .  
     
     
         6 . The host cell of  claim 5 , wherein the host cell 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 fragment of a first polypeptide having the amino acid sequence of SEQ ID NO: 3, wherein the fragment comprises at least 17 contiguous amino acid residues of the first polypeptide;    b) a naturally-occurring allelic variant of a first polypeptide having the amino acid sequence of SEQ ID NO: 3, wherein the first polypeptide is encoded by a nucleic acid molecule which hybridizes under stringent conditions with a nucleic acid molecule having of the nucleotide sequence of one of SEQ ID NOs: 1 and 2, or a complement thereof;    c) a polypeptide encoded by a nucleic acid molecule having a nucleotide sequence which is at least 40% identical to one of SEQ ID NOs: 1 and 2, or a complement thereof; and    d) a polypeptide having the amino acid sequence of about residues 18-467 of SEQ ID NO: 3.    
     
     
         9 . The isolated polypeptide of  claim 8  having the amino acid sequence SEQ ID NO: 3.  
     
     
         10 . The polypeptide of  claim 8 , wherein the amino acid sequence of the polypeptide further comprises a heterologous amino acid residue.  
     
     
         11 . An antibody which selectively binds with the polypeptide of  claim 8 .  
     
     
         12 . A method for producing a polypeptide selected from the group consisting of: 
 a) a polypeptide having the amino acid sequence of SEQ ID NO: 3;    b) a polypeptide comprising a fragment of a first polypeptide having the amino acid sequence of SEQ ID NO: 3, wherein the fragment comprises at least 17 contiguous amino acid residues of the first polypeptide; and    c) a naturally-occurring allelic variant of a first polypeptide having the amino acid sequence of SEQ ID NO: 3, wherein the first polypeptide is encoded by a nucleic acid molecule which hybridizes under stringent conditions with a nucleic acid molecule having the nucleotide sequence of one of SEQ ID NOs: 1 and 2, or a complement thereof;    the method 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, the method comprising: 
 a) contacting the sample with a compound which selectively binds with a polypeptide of  claim 8;  and  
 b) determining whether the compound binds with the polypeptide in the sample.  
 
     
     
         14 . The method of  claim 13 , wherein the compound is an antibody.  
     
     
         15 . A kit comprising a compound which selectively binds with 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, the method comprising: 
 a) contacting the sample with a nucleic acid probe or primer which selectively hybridizes with the nucleic acid molecule; and  
 b) determining whether the nucleic acid probe or primer binds with 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 with a nucleic acid molecule of  claim 1  and instructions for use.  
     
     
         19 . A method for identifying a compound which binds with a polypeptide of  claim 8 , the method comprising: 
 a) contacting the polypeptide, or a cell expressing the polypeptide with a test compound; and    b) determining whether the polypeptide binds with the test compound.    
     
     
         20 . The method of  claim 19 , wherein binding of the test compound with the polypeptide is detected by a method selected from the group consisting of: 
 a) detection of binding by direct detection of test compound/polypeptide binding;    b) detection of binding using a competition binding assay;    c) detection of binding using an assay for an activity characteristic of the polypeptide.    
     
     
         21 . A method for modulating the activity of a polypeptide of  claim 8 , the method comprising contacting the polypeptide or a cell expressing the polypeptide with a compound which binds with 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 , the method comprising: 
 a) contacting the polypeptide 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 . An antibody substance which selectively binds with the polypeptide of  claim 8 , wherein the antibody substance is made by providing the polypeptide to an immunocompetent vertebrate and thereafter harvesting blood or serum from the vertebrate.  
     
     
         24 . A method of treating a patient afflicted with a disorder associated with aberrant activity or expression of MLip-1 protein, the method comprising administering to the patient a compound which modulates the activity of the protein in an amount effective to modulate the activity of the protein in the patient, whereby at least one symptom of the disorder is alleviated.  
     
     
         25 . A method of treating a patient afflicted with a disorder associated with aberrant activity or expression of MLip-l protein, the method comprising administering to the patient, in an amount effective to modulate the activity of the protein in the patient, a compound selected from the group consisting of 
 i) the protein;    ii) a variant of the protein;    iii) a nucleic acid encoding the protein; and    iv) an antisense nucleic acid which is capable of annealing with either of an mRNA encoding the protein and a portion of a genomic DNA encoding the protein,    whereby at least one symptom of the disorder is alleviated.    
     
     
         26 . A method of diagnosing a disorder associated with aberrant activity or expression of MLip-1 protein, the method being selected from the group consisting of 
 (i) a method comprising assessing the level of expression of the gene encoding the protein in the patient and comparing the level of expression of the gene with the normal level of expression of the gene in a human not afflicted with the disorder, whereby a difference between the level of expression of the gene in the patient and the normal level is an indication that the patient is afflicted with the disorder and    (ii) a method comprising comparing a sequence selected from the group consisting of 
 (a) the nucleotide sequence of a nucleic acid encoding MLip-1 and  
 (b) the amino acid sequence of a portion of MLip-1 protein in a sample obtained from a patient with the same sequence in a sample obtained from a subject who is known not to be afflicted and not to be predisposed to becoming afflicted with the disorder, whereby a difference between the two sequences is an indication that the patient is afflicted with the disorder.  
   
     
     
         27 . A method of determining whether a patient is likely to become afflicted with a disorder associated with aberrant activity or expression of MLip-1 protein, the method comprising comparing a sequence selected from the group consisting of 
 (i) the nucleotide sequence of a nucleic acid encoding MLip-1 and    (ii) the amino acid sequence of a portion of MLip-1 protein in a sample obtained from a patient with the same sequence in a sample obtained from a subject who is known not to be afflicted and not to be predisposed to becoming afflicted with the disorder, whereby a difference between the two sequences is an indication that the patient is likely to become afflicted with the disorder.