A mitogen activated protein kinase inhibitor peptide which is covalently coupled to a fluorophore/with beta galactosidase or biotinyl enzymes, is new. A mitogen activated protein kinase inhibitor peptide which is covalently coupled to a fluorophore/with beta galactosidase or biotinyl enzymes. The enzymatic sequence is optionally surrounded by spacer. The export and localization sequence for intracellular signalling. The amino acids corresponding to docking domain of a mitogen activated protein kinase and allows the penetration of HIV-type I trans activating transcriptional activator protein in a cell. Independent claims are also included for: (1) a nucleic acid encoding the peptide； (2) a expression vector； and (3) a kit comprising the peptide and/or the expression vector.
