In 1993, a study by Greber, Willetts, Webster, and Helenius investigated the stepwise dismantling of adenovirus 2 during entry into cells. Adenoviruses enter host cells via receptor-mediated endocytosis and acid-activated penetration from endosomes into the cytosol, delivering their DNA genome into the nucleus. The study revealed that incoming adenovirus type 2 particles undergo a stepwise disassembly process necessary for virus progression in the entry pathway and genome release into the nucleus. This process involves the release of fibers, dissociation of penton base structures, degradation of proteins connecting DNA to the capsid, and elimination of capsid-stabilizing minor proteins. The uncoating process begins immediately upon endocytic uptake and ends with the uptake of dissociated hexon proteins and DNA into the nucleus. The study used quantitative biochemical and immunochemical methods combined with immunocytochemical techniques to analyze the uncoating process. Results showed that interactions holding the extracellular virus together are systematically eliminated in a series of distinct steps during the cell entry pathway. The study also identified that the virus's entry involves the dissociation of the fiber from the penton base and the virus particle, which is essential for endocytosis. The fibers dissociate from the viral DNA at an early stage of entry, and the DNA is released into the nucleus after penetration from endosomes. The study further demonstrated that the uncoating process involves proteolytic degradation of specific viral proteins, such as protein VI and hexon, which are essential for the virus to release its DNA into the nucleus. The study also showed that the hexon protein is the cause of a transient 65 kd band appearing at 40 min and for some smaller molecular mass bands. The results indicated that most viral proteins remain intact for long periods after penetration, with a subpopulation of hexons and the majority of protein VI undergoing proteolysis. This suggests that controlled proteolysis may play a role in the uncoating process, such as to dissociate the DNA from the inside surface of the capsid. The study concluded that adenovirus 2 undergoes multiple sequential uncoating steps as it moves from the cell surface via endosomes to the nuclear membrane. The virus particle, which is very stable outside the cell, is dismantled and weakened by the elimination of structural proteins upon entry so that it can efficiently release its DNA into the nucleus of the cell. The loss of specific proteins occurs by proteolytic degradation and selective dissociation. The specific interactions established during virus assembly are systematically broken down to allow the release of the genome and to affect its targeting to the nucleus. The uncoating process begins during endocytic uptake at the plasma membrane or immediately thereafter, with further changes taking place in the endosomal compartment and the cytosol. It culminates some 30 min after internalization withIn 1993, a study by Greber, Willetts, Webster, and Helenius investigated the stepwise dismantling of adenovirus 2 during entry into cells. Adenoviruses enter host cells via receptor-mediated endocytosis and acid-activated penetration from endosomes into the cytosol, delivering their DNA genome into the nucleus. The study revealed that incoming adenovirus type 2 particles undergo a stepwise disassembly process necessary for virus progression in the entry pathway and genome release into the nucleus. This process involves the release of fibers, dissociation of penton base structures, degradation of proteins connecting DNA to the capsid, and elimination of capsid-stabilizing minor proteins. The uncoating process begins immediately upon endocytic uptake and ends with the uptake of dissociated hexon proteins and DNA into the nucleus. The study used quantitative biochemical and immunochemical methods combined with immunocytochemical techniques to analyze the uncoating process. Results showed that interactions holding the extracellular virus together are systematically eliminated in a series of distinct steps during the cell entry pathway. The study also identified that the virus's entry involves the dissociation of the fiber from the penton base and the virus particle, which is essential for endocytosis. The fibers dissociate from the viral DNA at an early stage of entry, and the DNA is released into the nucleus after penetration from endosomes. The study further demonstrated that the uncoating process involves proteolytic degradation of specific viral proteins, such as protein VI and hexon, which are essential for the virus to release its DNA into the nucleus. The study also showed that the hexon protein is the cause of a transient 65 kd band appearing at 40 min and for some smaller molecular mass bands. The results indicated that most viral proteins remain intact for long periods after penetration, with a subpopulation of hexons and the majority of protein VI undergoing proteolysis. This suggests that controlled proteolysis may play a role in the uncoating process, such as to dissociate the DNA from the inside surface of the capsid. The study concluded that adenovirus 2 undergoes multiple sequential uncoating steps as it moves from the cell surface via endosomes to the nuclear membrane. The virus particle, which is very stable outside the cell, is dismantled and weakened by the elimination of structural proteins upon entry so that it can efficiently release its DNA into the nucleus of the cell. The loss of specific proteins occurs by proteolytic degradation and selective dissociation. The specific interactions established during virus assembly are systematically broken down to allow the release of the genome and to affect its targeting to the nucleus. The uncoating process begins during endocytic uptake at the plasma membrane or immediately thereafter, with further changes taking place in the endosomal compartment and the cytosol. It culminates some 30 min after internalization with