Scientific insights on a human and a fungal HDAC in A.nidulans

The severe growth defects of two A.nidulans strains expressing RpdA with two point-mutations of catalytically essential residues within the N-terminal domain confirmed that a loss of catalytic RpdA activity is responsible for defects in growth and sporulation of A.nidulans strains depleted in RpdA. Additionally the proper targeting of RpdA into the nucleus is independent on the catalytic HDAC activity since Venus-tagged mutated RpdA was detected in the nuclei of the corresponding expression strains. Expression of hsHDAC2 failed in A.nidulans mutants depleted for endogenous RpdA thus it is currently not possible to make any statement concerning the ability of a possible complementation. However due to the fact that hsHDAC1 was successfully expressed in A. nidulans but was not able to complement for depleted RpdA substantiate the assumption that indeed fungal-specific motifs of RpdA might be essential for its biological function in filamentous fungi.