RESUMO
Neuronal health is essential for the long-term integrity of the brain. In this study, we characterized the novel E3 ubiquitin ligase ring finger protein 157 (RNF157), which displays a brain-dominant expression in mouse. RNF157 is a homolog of the E3 ligase mahogunin ring finger-1, which has been previously implicated in spongiform neurodegeneration. We identified RNF157 as a regulator of survival in cultured neurons and established that the ligase activity of RNF157 is crucial for this process. We also uncovered that independently of its ligase activity, RNF157 regulates dendrite growth and maintenance. We further identified the adaptor protein APBB1 (amyloid beta precursor protein-binding, family B, member 1 or Fe65) as an interactor and proteolytic substrate of RNF157 in the control of neuronal survival. Here, the nuclear localization of Fe65 together with its interaction partner RNA-binding protein SART3 (squamous cell carcinoma antigen recognized by T cells 3 or Tip110) is crucial to trigger apoptosis. In summary, we described that the E3 ligase RNF157 regulates important aspects of neuronal development.
Assuntos
Ubiquitina-Proteína Ligases/metabolismo , Animais , Apoptose , Células Cultivadas , Dendritos/fisiologia , Células HEK293 , Histona Acetiltransferases/genética , Histona Acetiltransferases/metabolismo , Humanos , Camundongos , Camundongos Knockout , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Ligação Proteica , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/antagonistas & inibidores , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Ratos , Ratos Wistar , Ubiquitina-Proteína Ligases/antagonistas & inibidores , Ubiquitina-Proteína Ligases/genética , UbiquitinaçãoRESUMO
Myelination by oligodendrocytes in the CNS involves the migration to and recognition and ensheathment of axons. These distinct developmental phases of myelination are assumed to involve the interplay of a precisely regulated set of cell adhesion molecules expressed by both neurons and glial cells. These molecules remain largely unelucidated. In this paper we have identified a large (330 kDa) glycoprotein expressed by murine oligodendrocyte progenitor cells in vitro and in vivo that is downregulated as oligodendrocytes mature. Antigen-positive oligodendrocyte progenitor cells purified by panning develop into myelin-associated glycoprotein-positive oligodendrocytes and also adhere to cultured neurons. Polyclonal antibodies directed against the protein reduce the migration of oligodendrocyte progenitor cells. The observations suggest that the AN2 antigen may play a role in early stages of myelination.
