General Stability | Organism |
---|---|
molecular chaperone Hsp90 is a binding partner of isozyme PI4KIIbeta. Geldanamycin, a specific Hsp90 inhibitor, disrupts the Hsp90-PI4KIIbeta interaction and destabilizes PI4KIIbeta, reducing its half-life by 40% and increasing its susceptibility to ubiquitylation and proteasomal degradation. Cytosolic PI4KIIbeta is much more sensitive to geldanamycin treatment than is the integrally membrane-associated species. Stimuli such as PDGF receptor activation that also induce recruitment of the kinase to membranes disrupt the Hsp90-PI4KIIbeta interaction to a similar extent as inhibitor treatment | Homo sapiens |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
cytosol | isozyme PI4KIIbeta is distributed almost evenly between membranes and cytosol | Homo sapiens | 5829 | - |
membrane | isozyme PI4KIIalpha exists almost exclusively as a constitutively active integral membrane protein because of its palmitoylation | Rattus norvegicus | 16020 | - |
membrane | isozyme PI4KIIbeta is distributed almost evenly between membranes and cytosol | Homo sapiens | 16020 | - |
additional information | whereas the palmitoylated membrane-bound pool is catalytically active, the cytosolic kinase is inactive | Homo sapiens | - |
- |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | - |
- |
- |
Rattus norvegicus | - |
- |
- |
Posttranslational Modification | Comment | Organism |
---|---|---|
lipoprotein | isozyme PI4KIIalpha exists almost exclusively as a constitutively active integral membrane protein because of its palmitoylation | Rattus norvegicus |
Synonyms | Comment | Organism |
---|---|---|
phosphatidylinositol 4-kinase type IIbeta | - |
Homo sapiens |
PI4KIIalpha | - |
Rattus norvegicus |
PI4KIIbeta | - |
Homo sapiens |
type II phosphatidylinositol 4-kinase | - |
Homo sapiens |
type II phosphatidylinositol 4-kinase | - |
Rattus norvegicus |
General Information | Comment | Organism |
---|---|---|
additional information | molecular chaperone Hsp90 is a binding partner of isozyme PI4KIIbeta, PI4KIIbeta contains an Hsp90 interaction site, which most likely resides in the N-terminal lobe of the catalytic domain. PI4KIIbeta must bind to Hsp90 and is highly sensitive to its release, perhaps because a substantial portion of this isoform is cytosolic. Hsp90 selectively stabilizes the cytosolic pool of PI4KIIbeta.. Hsp90 protects PI4KIIbeta from degradation by the proteasome. Geldanamycin, a specific Hsp90 inhibitor, disrupts the Hsp90-PI4KIIbeta interaction and destabilizes PI4KIIbeta, reducing its half-life by 40% and increasing its susceptibility to ubiquitylation and proteasomal degradation. Cytosolic PI4KIIbeta is much more sensitive to geldanamycin treatment than is the integrally membrane-associated species. Stimuli such as PDGF receptor activation that also induce recruitment of the kinase to membranes disrupt the Hsp90-PI4KIIbeta interaction to a similar extent as inhibitor treatment. Dissociation of PI4KIIbeta from Hsp90 by exposure to geldanamycin results in transient translocation to membranes and increased kinase activity | Homo sapiens |
additional information | molecular chaperone Hsp90 is no binding partner of isozyme PI4KIIalpha, although also PI4KIIalpha contains an Hsp90 interaction site, which most likely resides in the N-terminal lobe of the catalytic domain, but PI4KIIalpha apparently does not require stabilization by Hsp90 binding because it associates strongly with membranes, even in the absence of palmitoylation | Rattus norvegicus |
physiological function | whereas the palmitoylated membrane-bound pool is catalytically active, the cytosolic kinase is inactive | Homo sapiens |