Literature summary for 2.7.1.67 extracted from

Jung, G.; Barylko, B.; Lu, D.; Shu, H.; Yin, H.; Albanesi, J.P.
Stabilization of phosphatidylinositol 4-kinase type IIbeta by interaction with Hsp90 (2011), J. Biol. Chem., 286, 12775-12784.

General Stability

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

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

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

Organism	UniProt	Comment	Textmining
Homo sapiens	-	-	-
Rattus norvegicus	-	-	-

Posttranslational Modification

Posttranslational Modification	Comment	Organism
lipoprotein	isozyme PI4KIIalpha exists almost exclusively as a constitutively active integral membrane protein because of its palmitoylation	Rattus norvegicus

Synonyms

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

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