Role Of A Penicillium Janthinillum GXCR P-Type Atpase Gene In Resistance To Copper Ion Toxicity

Although many heavy metals are essential, high heavy metal concentrations are toxic to organism. Resistance to high heavy metal concentrations is achieved by a variety of mechanisms both in bacteria and in fungi. Copper-transporting P-type ATPases are found in eukaryotes as well, where they play a major role in intracellular copper transport.DNA sequence which was partial homogeneous with Copper-transporting P-type ATPase gene was amplified from filaceous fungi Penicillium janthinillum GXCR by designed degenerate primers based on the reported amino acid sequence. A RNAi expression vector pCPXBn-ihp1 was constructed aimed at interfering the copper-transporting P-type ATPase gene of Penicillium janthinillum GXCR and then transfered into protoplasts of GXCR with PEG/CaCl₂ method. Three mutants were identified by PCR and Southern hybriding blot. The expression level of Copper-transporting P-type ATPase genes of the three mutants decreased by 24.92%, 40.23% and 32.89%, respectively, measured with real-time fluorescence quantitative PCR (Q-PCR) . Compared to the wild type, the mutants' resistant capacity to Cu²⁺ declined and indicates that the Copper-transporting P-type ATPase gene plays an important role in resistance to heavy metal ion such as Cu²⁺ in filaceous fungi Penicillium janthinillum GXCR...