PROTECTIVE ACTION dominant negative mutant protein KRP FROM inhibiting the activity of cyclin-CDK KRP wildtype

摘要

1. An isolated mutant CKI polypeptide (an inhibitor of cyclin-dependent kinase) plants, comprising: a CKI amino acid sequence, having at least one modification relative to a wild-type CKI polypeptide plant CKI polypeptide of said wild-type, comprising (a) a cyclin binding region to impart binding affinity for a cyclin and (b) CDK-binding region to impart a binding affinity for CDK; ! wherein at least one said modification is within the CDK-binding region relative to impart wild-type CKI polypeptide, a modified binding affinity of the mutant CKI polypeptide for the CDK; ! wherein the mutant CKI polypeptide substantially maintains a relatively CKI polypeptide, wild-type binding affinity for the cyclin; and! where the mutant CKI polypeptide can compete with wild-type CKI specified for binding to the CDK-binding region. ! 2. The mutant plant CKI polypeptide of claim 1, wherein said polypeptide is a wild-type plant CKI is a member of KIP-related proteins (KRP). ! 3. The mutant plant CKI polypeptide of claim 2, wherein said KRP family member is a polypeptide CKI Brassica napus, Arabidopsis thaliana, Glycine max, maize, wheat, rice, alfalfa, cotton, or poplar. ! 4. The mutant plant CKI polypeptide of claim 2, wherein said KRP family member is a polypeptide KRP1 Arabidopsis or Brassica. ! 5. The mutant plant CKI polypeptide of claim 2, wherein at least one said modification is within the region corresponding to amino acids 145-168 KRP1 Brassica (BnKRP1). ! 6. The mutant plant CKI polypeptide of claim 5, which comprises at least two modifications within a region corresponding to amino acids 145-168 KRP1 Brassic