LMPD Database

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LMP002545

UniProt Annotations

Entry Information
Gene Namephosphatidylinositol 4-kinase, catalytic, beta
Protein EntryQ9UBF8_HUMAN
UniProt IDQ9UBF8
SpeciesHuman
Comments
Comment typeDescription
Alternative ProductsEvent=Alternative splicing; Named isoforms=3; Name=1 ; Synonyms=NPIK-B ; IsoId=Q9UBF8-1; Sequence=Displayed; Name=2 ; Synonyms=NPIK-C ; IsoId=Q9UBF8-2; Sequence=VSP_050627; Note=Contains a phosphoserine at position 294.; Name=3; IsoId=Q9UBF8-3; Sequence=VSP_037133;
Catalytic ActivityATP + 1-phosphatidyl-1D-myo-inositol = ADP + 1-phosphatidyl-1D-myo-inositol 4-phosphate.
Enzyme RegulationInhibited by wortmannin. Increased kinase activity upon interaction with NCS1/FREQ (By similarity).
FunctionPhosphorylates phosphatidylinositol (PI) in the first committed step in the production of the second messenger inositol- 1,4,5,-trisphosphate (PIP). May regulate Golgi disintegration/reorganization during mitosis, possibly via its phosphorylation. Involved in Golgi-to-plasma membrane trafficking (By similarity).
InteractionQ9H3P7:ACBD3; NbExp=4; IntAct=EBI-1053214, EBI-1791792; P03495:NS (xeno); NbExp=2; IntAct=EBI-1053214, EBI-2548993;
Sequence CautionSequence=BAA21661.1; Type=Erroneous initiation; Note=Translation N-terminally shortened.; Evidence= ; Sequence=CAH70326.1; Type=Erroneous gene model prediction; Evidence= ; Sequence=EAW53450.1; Type=Erroneous gene model prediction; Evidence= ;
SimilarityBelongs to the PI3/PI4-kinase family. Type III PI4K subfamily.
SimilarityContains 1 PI3K/PI4K domain. {ECO
SimilarityContains 1 PIK helical domain. {ECO
Subcellular LocationEndomembrane system. Mitochondrion outer membrane; Peripheral membrane protein. Rough endoplasmic reticulum membrane; Peripheral membrane protein. Golgi apparatus. Cytoplasm, perinuclear region. Note=Found in the outer membrane of mitochondria and membranes of the rough endoplasmic reticulum. Recruited to the Golgi complex by the small GTPase ARF to stimulate the synthesis of phosphatidylinositol 4,5-bisphosphate (PIP2) on the Golgi complex.
SubunitInteracts with ARF1 and ARF3 in the Golgi complex, but not with ARF4, ARF5 or ARF6. Interacts with NCS1/FREQ in a calcium-independent manner (By similarity). Interacts with CALN1/CABP8 and CALN2/CABP7; in a calcium-dependent manner (By similarity). This binding competes with NCS1/FREQ binding (By similarity).
Tissue SpecificityWidely expressed with highest levels in heart, skeletal muscle, pancreas, testis and ovary. Weakly expressed in liver. {ECO