Methods and compositions for cell-cycle regulation

Abstract

In some aspects, the invention provides methods and compositions including HTm4, an HTm4 activator, and/or an HTm4 variant to potentiate a KAP phosphatase activity and or inhibit a CDK2 kinase activity. In some embodiments, a functional C-terminal fragment of HTm4 is provided. In other aspects, the invention provides methods and compositions including an HTm4 inhibitor to inactivate or decrease the activation of a KAP phospatase activity and/or activate or relieve the inhibition on a CDK2 kinase activity. Certain aspects of the invention relate to therapeutic compositions and methods for either inhibiting or promoting cell proliferation.

1 .- 3 . (canceled) 
     
     
         4 . A method of upregulating or increasing cell cycle progression, the method comprising:
 contacting a cell expressing HTm4 with an HTm4 inhibitor in an effective amount to inhibit HTm4 function.   
     
     
         5 . The method of  claim 4 , wherein the inhibitor comprises an HTm4 antibody or antibody fragment, or a nucleic acid aptamer, that specifically binds to one or more epitopes of HTm4. 
     
     
         6 .- 7 . (canceled) 
     
     
         8 . An isolated HTm4 C-terminal fragment. 
     
     
         9 . The isolated HTm4 C-terminal fragment of  claim 8 , wherein the HTm4 C-terminal fragment comprises an amino acid sequence of SEQ ID NO: 3, but not the amino acid sequence of full-length HTm4. 
     
     
         10 . A pharmaceutical preparation comprising the isolated HTm4 C-terminal fragment of  claim 8  or  9 . 
     
     
         11 .- 12 . (canceled) 
     
     
         13 . The method of  claim 5 , wherein the antibody, antibody fragment, or nucleic acid aptamer specifically binds to one or more C-terminal epitopes of HTm4.