High impact information on JUB

• In vitro analyses revealed that Ajuba induces the autophosphorylation and consequent activation of Aurora-A [1].
• A two-hybrid screen identified the LIM protein Ajuba as an Aurora-A binding protein [1].
• We show that cells from Ajuba null mice are inhibited in their migration, without associated abnormality in adhesion to extracellular matrix proteins, cell spreading, or integrin activation [2].
• In migrating primary mouse embryonic fibroblasts (MEFs) from Ajuba(-/-) mice the level of PI(4,5)P2 was decreased with a corresponding increase in the level of the substrate PI(4)P [3].
• The LIM protein Ajuba regulates phosphatidylinositol 4,5-bisphosphate levels in migrating cells through an interaction with and activation of PIPKI alpha [3].

Biological context of JUB

• Depletion of Ajuba prevented activation of Aurora-A at centrosomes in late G2 phase and inhibited mitotic entry [1].
• Thus, in addition to its effects upon Rac activity Ajuba can also influence cell migration through regulation of PI(4,5)P2 synthesis through direct activation of PIPKIalpha enzyme activity [3].
• To understand Ajuba's role in signal transduction pathways, we performed a yeast two-hybrid screen with the LIM domain region of Ajuba [4].
• The Zyxin/Ajuba family of cytosolic LIM domain-containing proteins has the potential to shuttle from sites of cell adhesion into the nucleus and thus can be candidate transducers of environmental signals [4].
• Here we show that, in primary keratinocytes, the LIM domain protein Ajuba is recruited to cadherin-dependent cell-cell adhesive complexes in a regulated manner [5].

Anatomical context of JUB

• Localization of PI(4,5)P2 synthesis and PIPKIalpha in the leading lamellipodia and membrane ruffles, respectively, of migrating Ajuba(-/-) MEFs was impaired [3].
• Keratinocytes from Ajuba null mice exhibit abnormal cell-cell junction formation and/or stability and function [5].
• At cadherin adhesive complexes Ajuba interacts with alpha-catenin, and alpha-catenin is required for efficient recruitment of Ajuba to cell junctions [5].
• Ajuba is expressed in cerebellum, cortex, hippocampus, and retina and also in organs outside the CNS [6].

Physical interactions of JUB

• Ajuba LIM domains directly bind to Gfi1, but the association is not SNAG domain-dependent [7].

Other interactions of JUB

• LATS2 was localized to the centrosomes throughout the cell cycle and was associated with Ajuba during mitosis, contributing to latter's mitotic phosphorylation [8].

References