The present invention relates generally to amino acid sequences obtainable from SOCS proteins and which are capable of interacting with intracellular molecules. The present invention further relates to nucleic acid molecules encoding said amino acid sequences. The amino acid sequences and the nucleic acid molecules encoding same of the present invention are useful in modulating degradation of proteinaceous molecules such as but not limited to SOCS proteins and proteinaceous molecules associate therewith. The present invention provides a mechanism for modulating cytokine or cytokine-like molecule signaling by modulating the degradation of activated signal transduction molecules or their negative regulators, i.e. the SOCS proteins.