polymerase 1 & transcript release factor; ; Cavin-1 (PTRF, FKSG13)

Function: - role in caveolae formation & organization - required for sequestration of mobile caveolin into immobile caveolae - termination of transcription by RNA polymerase 1 involves pausing of transcription by TTF1, & the dissociation of the transcription complex, releasing pre-rRNA & RNA polymerase 1 from the template - PTRF is required for dissociation of the ternary transcription complex - phosphorylated - present in active & inactive forms - changes in phosphorylation pattern may alter activity - 5 truncated forms are found in the caveolae - these are thought to be the result of proteolysis & may be phosphorylation-dependent - interacts with RNA polymerase 1 & TTF1 - binds the 3' end of pre-rRNA - interacts with transcription factor ZNF148 - interacts with LIPE in the adipocyte cytoplasm Structure: belongs to the PTRF/SDPR family Compartment: - membrane, caveola, plasma membrane - microsome, endoplasmic reticulum - cytoplasm, mitochondria, nucleus - found at the surface of the caveolae - also found in the plasma membrane, microsomal & cytosolic fractions - found at a low level in the mitochondrial & nuclear fractions - translocates to the cytoplasm from the caveolae upon insulin stimulatio - CAV1 is necessary to recruit it to the cell membrane (putative) - co-localizes with CAV1 in lipid rafts in adipocytes Alternative splicing: named isoforms=3 Pathology: - defects in PTRF are the cause of congenital generalized lipodystrophy type 4

General

mitochondrial protein nuclear protein phosphoprotein RNA-binding protein

Properties

SIZE: entity length = 390 aa MW = 43 kD COMPARTMENT: mitochondria cytoplasm cell nucleus endoplasmic reticulum MOTIF: acetylation site SITE: N-TERMINUS EFFECTOR-BOUND: acetyl Ser phosphorylation site {S36} Ser phosphorylation site {S40} Ser phosphorylation site {S118} Tyr phosphorylation site {Y156} Ser phosphorylation site {S167} Ser phosphorylation site {S175} coiled coil {199-282} MOTIF: Ser phosphorylation site {S202} Ser phosphorylation site {S203} Ser phosphorylation site {S300} Thr phosphorylation site {T302} Tyr phosphorylation site {Y308} Ser phosphorylation site {S365} Ser phosphorylation site {S366} Thr phosphorylation site {T376} Ser phosphorylation site {S379} Ser phosphorylation site {S387} Ser phosphorylation site {S389}

Database Correlations

OMIM correlations UniProt Q6NZI2 Entrez Gene 284119 Kegg hsa:284119

References

UniProt :accession Q6NZI2