Patent ID: 7968281

Claim:
A method for identifying an agent that modulates methylation of a retinoblastoma peptide by SMYD3, said method comprising the steps of: a. contacting an SMYD3 polypeptide having a methyltransferase activity selected from the group consisting of: i. a polypeptide comprising the amino acid sequence of SEQ ID NO: 2; ii. a polypeptide that comprises the amino acid sequence of positions 117 to 246 of the amino acid sequence of SEQ ID NO: 2, wherein said polypeptide has a methyltransferase activity equivalent to the polypeptide consisting of the amino acid sequence of SEQ ID NO:2; iii. a polypeptide that comprises the amino acid sequence of positions 1 to 250 of the amino acid sequence of SEQ ID NO: 2; iv. a polypeptide that comprises the amino acid sequence of positions 45 to 428 of the amino acid sequence of SEQ ID NO: 2; v. a polypeptide that comprises the amino acid sequence of SEQ ID NO: 2 in which the amino acids of positions 1 to 30 have been deleted; vi. a polypeptide that comprises the amino acid sequence of SEQ ID NO: 2 in which the amino acids of positions 1 to 44 are deleted; vii. a polypeptide that comprises the amino acid sequence of SEQ ID NO: 2 in which the amino acids of positions 1 to 20 are deleted; and viii. a polypeptide that comprises the amino acid sequence of SEQ ID NO: 2 in which the amino acids of positions 1 to 10 are deleted; with the retinoblastoma peptide to be methylated and a cofactor in the presence of the agent under conditions suitable for methylation of the retinoblastoma peptide; b. detecting the methylation level of the retinoblastoma peptide; and c. comparing the methylation level of step (b) with a control level detected in the absence of the agent, wherein an increase or decrease in the methylation level compared to the control level indicates that the agent modulates the methylation of the retinoblastoma peptide by SMYD3.