GTP binding by class II transactivator: role in nuclear import.

Transactivator Regulates Its Nuclear Export The GTP-Binding Domain of Class II

Novel properties of the protein kinase CK2-site-regulated nuclear- localization sequence of the interferon-induced nuclear factor IFI 16.

Members of the interferon-induced class of nuclear factors possess a putative CcN motif, comparable with that within proteins such as the simian virus 40 large tumour antigen (T-ag), which confers phosphorylation-mediated regulation of nuclear-localization sequence (NLS)-dependent nuclear import. Here we examine the functionality of the interferon-induced factor 16 (IFI 16) CcN motif, demonstra...

Reduced IL-4-, lipopolysaccharide-, and IFN-gamma-induced MHC class II expression in mice lacking class II transactivator due to targeted deletion of the GTP-binding domain.

Class II transactivator (CIITA) is an unusual transcriptional coactivator in that it contains a functionally important, GTP-binding consensus domain. To assess the functional role of the GTP-binding domain of CIITA in vivo, we have generated knockout mice that bear a mutation in the CIITA gene spanning the GTP-binding domain. Upon analysis, these mice show no detectable CIITA mRNA; hence, they ...

Phosphorylation of class II transactivator regulates its interaction ability and transactivation function.

The MHC class II transactivator (CIITA) plays a central role in adaptive immune responses by controlling the expression of MHC class II genes. CIITA binds DNA-binding proteins and co-activator proteins to form an enhanceosome complex necessary for MHC class II gene expression. Here we demonstrate that CIITA interactions depend upon the phosphorylation status of CIITA. Hyper-phosphorylated CIITA...

Self-association of class II transactivator correlates with its intracellular localization and transactivation.

Class II transactivator (CIITA) is the master regulator of major histocompatibility complex class II genes that regulates both B lymphocyte-specific and interferon gamma-inducible expression. Here we identify protein regions and examine mechanisms that determine the intracellular distribution of CIITA. We show that two separate regions of CIITA mediate nuclear export: amino acids 1-114 and 408-...