COMPOSITIONS AND METHODS FOR MODULATION OF PLK1 KINASE ACTIVITY
First Claim
1. A method of activating a polo-like kinase-1 (Plk1) protein, the method comprising incubating a Plk1 protein in a buffer comprising (i) a divalent cation selected from the group consisting of manganese, calcium, nickel, and zinc and (ii) adenosine triphosphate (ATP), wherein the divalent cation and ATP are present in amounts sufficient to increase the kinase activity of the Plk1 protein.
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Accused Products
Abstract
Described are compositions and methods for activating a Plk1 protein as well as phospho-specific anti-Myt1 antibodies that can be used to detect phosphorylation of Myt1. Activated Plk1 protein, phospho-specific anti-Myt1 antibodies, and/or Plk1 substrates can be used in screening assays to identify compounds that modulate the ability of Plk1 to phosphorylate and/or bind to a Plk1 substrate.
15 Citations
75 Claims
- 1. A method of activating a polo-like kinase-1 (Plk1) protein, the method comprising incubating a Plk1 protein in a buffer comprising (i) a divalent cation selected from the group consisting of manganese, calcium, nickel, and zinc and (ii) adenosine triphosphate (ATP), wherein the divalent cation and ATP are present in amounts sufficient to increase the kinase activity of the Plk1 protein.
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19. A method of detecting the kinase activity of a Plk1 protein, the method comprising:
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contacting a Plk1 protein with a Plk1 substrate under conditions effective to permit phosphorylation of the Plk1 substrate, wherein the Plk1 substrate is a polypeptide comprising full length Myt1 or a fragment of Myt1 that is subject to phosphorylation by Plk1 on a threonine residue that corresponds to position 495 of Myt1; contacting the Plk1 substrate with a phospho-specific anti-pT495 Myt1 antibody; and measuring binding of the antibody to the Plk1 substrate to thereby detect phosphorylation of the Plk1 substrate; wherein phosphorylation of the Plk1 substrate indicates kinase activity of the Plk1 protein. - View Dependent Claims (20, 23, 27, 28)
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22. A method of identifying a compound that inhibits phosphorylation of a Plk1 substrate, the method comprising:
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contacting, in the presence of a candidate compound, a Plk1 protein with a Plk1 substrate, wherein the Plk1 substrate is a polypeptide comprising full length Myt1 or a fragment of Myt1 that is subject to phosphorylation by Plk1 on a threonine residue that corresponds to position 495 of Myt1; contacting the Plk1 substrate with a phospho-specific anti-pT495 Myt1 antibody; and measuring binding of the antibody to the Plk1 substrate to thereby detect phosphorylation of the Plk1 substrate; wherein decreased phosphorylation of the Plk1 substrate in the presence of the candidate compound as compared to phosphorylation of the Plk1 substrate that occurs in the absence of the candidate compound indicates that the candidate compound inhibits phosphorylation of the Plk1 substrate by the Plk1 protein.
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32. An isolated peptide that is less than 50 amino acids in length and comprises SEQ ID NO:
- 4, SEQ ID NO;
5, SEQ ID NO;
6, SEQ ID NO;
7, SEQ ID NO;
8, SEQ ID NO;
9, SEQ ID NO;
10, SEQ ID NO;
11, SEQ ID NO;
12, or a variant thereof, wherein the variant is a phosphorylation substrate of Plk1. - View Dependent Claims (33, 34, 35, 36, 37)
- 4, SEQ ID NO;
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38. An isolated antibody that specifically binds to a peptide whose amino acid sequence consists of SEQ ID NO:
- 4, SEQ ID NO;
5, SEQ ID NO;
6, SEQ ID NO;
7, SEQ ID NO;
8, SEQ ID NO;
9, SEQ ID NO;
10, SEQ ID NO;
11, SEQ ID NO;
12, or SEQ ID NO;
13. - View Dependent Claims (39)
- 4, SEQ ID NO;
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40. A method of generating an immune response in a mammal, the method comprising administering to the mammal an effective amount of the peptide of claim to 31.
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42. A method of detecting the kinase activity of a Plk1 protein, the method comprising:
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contacting a Plk1 protein with a Plk1 substrate under conditions effective to permit phosphorylation of the Plk1 substrate, wherein the Plk1 substrate is a polypeptide comprising a CENPB protein or a fragment of a CENPB protein that is subject to phosphorylation by Plk1; and measuring phosphorylation of the Plk1 substrate; wherein phosphorylation of the Plk1 substrate indicates kinase activity of the Plk1 protein. - View Dependent Claims (43, 44, 45, 46, 48, 49, 50, 51, 53)
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47. A method of identifying a compound that inhibits phosphorylation of a Plk1 substrate, the method comprising:
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contacting, in the presence of a candidate compound, a Plk1 protein with a Plk1 substrate, wherein the Plk1 substrate is a polypeptide comprising a CENPB protein or a fragment of a CENPB protein that is subject to phosphorylation by Plk1; and measuring phosphorylation of the Plk1 substrate; wherein decreased phosphorylation of the Plk1 substrate in the presence of the candidate compound as compared to phosphorylation of the Plk1 substrate that occurs in the absence of the candidate compound indicates that the candidate compound inhibits phosphorylation of the Plk1 substrate by the Plk1 protein.
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52. A method for identifying a compound that inhibits an interaction between a Plk1 protein and a Plk1 substrate, the method comprising:
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contacting, in the presence of a candidate compound, a Plk1 protein with a Plk1 substrate, wherein the Plk1 substrate is a polypeptide comprising a CENPB protein or a fragment of a CENPB protein that binds to Plk1; and measuring binding of the Plk1 protein to the Plk1 substrate; wherein decreased binding of the Plk1 protein to the Plk1 substrate in the presence of the candidate compound as compared to binding of the Plk1 protein to the Plk1 substrate that occurs in the absence of the candidate compound indicates that the candidate compound inhibits an interaction between the Plk1 protein and the Plk1 substrate.
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- 54. A method of inhibiting phosphorylation of a CENPB protein by a Plk1 protein, the method comprising administering to a subject an effective amount of a compound that inhibits phosphorylation of a CENPB protein by a Plk1 protein.
- 56. A method of inhibiting an interaction between a Plk1 protein and a CENPB protein, the method comprising administering to a subject an effective amount of a compound that inhibits an interaction between a Plk1 protein and a CENPB protein.
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62. A method for evaluating the efficacy of an anti-Plk1 agent, the method comprising:
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providing a biological sample obtained from a subject to whom an anti-Plk1 agent has been administered; and detecting phosphorylation of a CENPB protein in the biological sample;
wherein a decreased level of phosphorylation of the CENPB protein as compared to the level of phosphorylation in a biological sample taken from another subject or from the subject prior to administration of the anti-Plk1 agent indicates that the anti-Plk1 therapy is effective. - View Dependent Claims (63, 64, 65)
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- 66. An isolated peptide that is less than 50 amino acids in length and comprises a fragment of a CENPB protein that is subject to phosphorylation by Plk1 on a serine residue that corresponds to position 43 of CENPB, on a serine residue that corresponds to position 156 of CENPB, on a threonine residue that corresponds to position 169 of CENPB, on a serine residue that corresponds to position 307 of CENPB, or on a threonine residue that corresponds to position 396 of CENPB.
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67. An isolated peptide that is less than 50 amino acids in length and comprises SEQ ID NO:
- 21, SEQ ID NO;
22, SEQ ID NO;
23, SEQ ID NO;
24, or SEQ ID NO;
25, or a variant thereof, wherein the variant is a phosphorylation substrate of Plk1. - View Dependent Claims (68, 69, 70)
- 21, SEQ ID NO;
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75. A method for generating a compound that inhibits the interaction between a Plk1 protein and a CENPB protein, the method comprising:
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providing a three-dimensional structure of a molecule or a molecular complex comprising;
(a) a Plk1 protein or a CENPB-binding fragment thereof;
(b) a CENPB protein or a Plk1-binding fragment thereof;
or (c) a molecular complex comprising (a) and (b);designing, based on the three-dimensional structure, a compound comprising a region that inhibits the interaction between a Plk1 protein and a CENPB protein; and producing the compound.
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Specification