PTRF explained

Polymerase I and transcript release factor, also known as Cavin1, Cavin-1 or PTRF, is a protein which in humans is encoded by the PTRF gene.^{[1] [2]}

Function

PTRF (Cavin1) has been shown to be crucial for caveola formation and function.^[3] Deformation caveolae promotes the translocation of cavin-1 from caveolae to the nucleus^[4]

Termination of RNA polymerase I catalyzed transcription is a 2-step process that involves pausing of transcription elongation and release of both the pre-ribosomal RNA and Pol I from the DNA template. The pausing is mediated by TTF1 and PTRF.^{[5] [6]}

PTRF is a soluble protein containing putative leucine zipper, nuclear localization signal, and PEST domains.^[7]

Interactions

PTRF (Cavin1) forms trimers with Cavin2 and Cavin3 in caveola formation and has been shown to interact with other membrane associating proteins such as EHD2 and caveolins.^[8]

PTRF has been shown to interact with ZNF148.^[9]

Further reading

• Jansa P, Mason SW, Hoffmann-Rohrer U, Grummt I . Cloning and functional characterization of PTRF, a novel protein which induces dissociation of paused ternary transcription complexes . The EMBO Journal . 17 . 10 . 2855–2864 . May 1998 . 9582279 . 1170626 . 10.1093/emboj/17.10.2855 .
• Hasegawa T, Takeuchi A, Miyaishi O, Xiao H, Mao J, Isobe K . PTRF (polymerase I and transcript-release factor) is tissue-specific and interacts with the BFCOL1 (binding factor of a type-I collagen promoter) zinc-finger transcription factor which binds to the two mouse type-I collagen gene promoters . The Biochemical Journal . 347 Pt 1 . Pt 1 . 55–59 . April 2000 . 10727401 . 1220930 . 10.1042/0264-6021:3470055 .
• Aboulaich N, Vainonen JP, Strålfors P, Vener AV . Vectorial proteomics reveal targeting, phosphorylation and specific fragmentation of polymerase I and transcript release factor (PTRF) at the surface of caveolae in human adipocytes . The Biochemical Journal . 383 . Pt 2 . 237–248 . October 2004 . 15242332 . 1134064 . 10.1042/BJ20040647 .
• Rush J, Moritz A, Lee KA, Guo A, Goss VL, Spek EJ, Zhang H, Zha XM, Polakiewicz RD, Comb MJ . 6 . Immunoaffinity profiling of tyrosine phosphorylation in cancer cells . Nature Biotechnology . 23 . 1 . 94–101 . January 2005 . 15592455 . 10.1038/nbt1046 . 7200157 .
• Zhang Y, Wolf-Yadlin A, Ross PL, Pappin DJ, Rush J, Lauffenburger DA, White FM . Time-resolved mass spectrometry of tyrosine phosphorylation sites in the epidermal growth factor receptor signaling network reveals dynamic modules . Molecular & Cellular Proteomics . 4 . 9 . 1240–1250 . September 2005 . 15951569 . 10.1074/mcp.M500089-MCP200 . free .
• Aboulaich N, Ortegren U, Vener AV, Strålfors P . Association and insulin regulated translocation of hormone-sensitive lipase with PTRF . Biochemical and Biophysical Research Communications . 350 . 3 . 657–661 . November 2006 . 17026959 . 10.1016/j.bbrc.2006.09.094 .
• Olsen JV, Blagoev B, Gnad F, Macek B, Kumar C, Mortensen P, Mann M . Global, in vivo, and site-specific phosphorylation dynamics in signaling networks . Cell . 127 . 3 . 635–648 . November 2006 . 17081983 . 10.1016/j.cell.2006.09.026 . 7827573 . free .

Notes and References

1. Web site: Entrez Gene: PTRF polymerase I and transcript release factor.
2. Web site: CAVIN1 Symbol Report HUGO Gene Nomenclature Committee. www.genenames.org. 2017-05-30.
3. Hill MM, Bastiani M, Luetterforst R, Kirkham M, Kirkham A, Nixon SJ, Walser P, Abankwa D, Oorschot VM, Martin S, Hancock JF, Parton RG . 6 . PTRF-Cavin, a conserved cytoplasmic protein required for caveola formation and function . Cell . 132 . 1 . 113–124 . January 2008 . 18191225 . 2265257 . 10.1016/j.cell.2007.11.042 .
4. Qifti A, Balaji S, Scarlata S . Deformation of caveolae impacts global transcription and translation processes through relocalization of cavin-1 . The Journal of Biological Chemistry . 298 . 6 . 102005 . June 2022 . 35513070 . 9168624 . 10.1016/j.jbc.2022.102005 . free .
5. Mason SW, Sander EE, Grummt I . Identification of a transcript release activity acting on ternary transcription complexes containing murine RNA polymerase I . The EMBO Journal . 16 . 1 . 163–172 . January 1997 . 9009277 . 1169623 . 10.1093/emboj/16.1.163 .
6. Jansa P, Mason SW, Hoffmann-Rohrer U, Grummt I . Cloning and functional characterization of PTRF, a novel protein which induces dissociation of paused ternary transcription complexes . The EMBO Journal . 17 . 10 . 2855–2864 . May 1998 . 9582279 . 1170626 . 10.1093/emboj/17.10.2855 .
7. Aboulaich N, Vainonen JP, Strålfors P, Vener AV . Vectorial proteomics reveal targeting, phosphorylation and specific fragmentation of polymerase I and transcript release factor (PTRF) at the surface of caveolae in human adipocytes . The Biochemical Journal . 383 . Pt 2 . 237–248 . October 2004 . 15242332 . 1134064 . 10.1042/BJ20040647 .
8. Kovtun O, Tillu VA, Ariotti N, Parton RG, Collins BM . Cavin family proteins and the assembly of caveolae . Journal of Cell Science . 128 . 7 . 1269–1278 . April 2015 . 25829513 . 4379724 . 10.1242/jcs.167866 .
9. Hasegawa T, Takeuchi A, Miyaishi O, Xiao H, Mao J, Isobe K . PTRF (polymerase I and transcript-release factor) is tissue-specific and interacts with the BFCOL1 (binding factor of a type-I collagen promoter) zinc-finger transcription factor which binds to the two mouse type-I collagen gene promoters . The Biochemical Journal . 347 Pt 1 . Pt 1 . 55–59 . April 2000 . 10727401 . 1220930 . 10.1042/0264-6021:3470055 .