The HN protein of Newcastle disease virus induces cell apoptosis through the induction of lysosomal membrane permeabilization
Fig 9
A mechanism model showing the HN protein of NDV triggers LMP and promotes apoptosis.
NDV enters host cells and utilizes its genome for transcription and translation of the HN protein. The HN protein digests the sialic acid at the end of the glycan chains of LAMP1 and LAMP2 via its sialidase activity, leading to desialylation. The desialylated LAMP1 and LAMP2 undergo deglycosylation and degradation in the lysosome by CTSB, leading to LMP and the leakage of CTSB and CTSD. Consequently, these translocated CTSB and CTSD promote the degradation of Bcl-2, the cleavage of Bid into tBid, and the mitochondrial translocation of Bax, thereby inducing MOMP. This process further exacerbates LMP by inducing ROS release while simultaneously activating mitochondria-dependent apoptosis through the release of Cyt C.