GMP-1 (Gap Modifying Protein 1, SUMO-1)

Transport of macromolecules between the nucleus and cytoplasm occurs bi-directionally and is mediated by nuclear pore complexes (NPCs). NPCs are large supermolecular structures that span the nuclear envelope. Although ions, metabolites, and small macromolecules can passively diffuse through the NPC, most larger macromolecules such as proteins and ribonucleoproteins (RNPs) must be transported across the NPC by specific signal- and energy -dependent mechanisms. The Ran protein is required for the bi-directional transport of proteins and RNPs across the NPC. Ran is thought to operate in much the same fashion as other Ras-like GTPases acting as a molecular switch by cycling between the GTP bound and GDP bound forms. Nucleotide exchange by Ran is catalyzed by the GTP exchange factor RCC1, while GTP hydrolysis is catalyzed by the GTPase-activating protein RanGAP1. Two other proteins which bind Ran-GTP and possibly affect GTP hydrolysis include RanBP1 and RanBP2 (Nup 358). The mammalian RanGap-1 protein was originally purified from HeLa cells as a 65-70kD homodimer. Subsequent studies have demonstrated that RanGAP1 is highly concentrated at the cytoplasmic periphery of the NPC where it associates with RanBP2. This interaction requires the RanGap1 protein to be conjugated to a ~17kD ubiquitin-like protein termed GMP1 (Gap modifying protein 1) or SUMO-1 (small ubiquitin-related modifier). The unmodified 70kD form of RanGAP1 is exclusively cytoplasmic, whereas the 90-kD modified form of RanGap1 associates with the cytoplasmic fibers of the NPC. Therefore, the ubiquitin-like GMP1 (SUMO-1) protein functions in a novel way by modulating the partitioning of RanGAP1 between the cytoplasm and NPC. As described above, GMP1 (SUMO-1) is a small polypeptide which shares homology with ubiquitin and appears to be involved in protein targeting.\n\nApplications:\nSuitable for use in ELISA, Western Blot and Immunofluorescence. Other applications have not been tested.\n\nRecommended Dilution:\nELISA: 0.1-1ug/ml\nWestern Blot: 0.1-1ug/ml\nImmunofluorescence: 10-20ug/ml\nOptimal dilutions to be determined by the researcher.\n\nPositive Controls: \nRat liver nuclear envelopes, total lysates derived from NIH 3T3 and HeLa cells.\n\nStorage and Stability:\nMay be stored at 4 degrees C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Aliquots are stable for at least 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.

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SPECIFICATIONS

Catalog Number

G8245

Size

100ug

Applications

ELISA, IF, WB

Hosts

Mouse

Reactivities

Hum, Mouse, Rat

Form

Supplied as a liquid in PBS, pH 7.4, 0.1% sodium azide.

P Type

Mab

Purity

Purified by Protein A chromatography

Isotype

IgG1,k

References

1. Bischoff, F.R., et al; Proc. Natl. Acad. Sci. USA 91:2587-2591(1994) 2. DeGregori, J. et al; Genes Dev. 8:265-276(1994) 3. Bischoff, F.R., et al; Proc. Natl. Acad. Sci. USA 92:1749-1753(1995) 4. Bischoff, F.R. et al; EMBO J. 14:705-715(1995) 5. Matunis, M.J. et al; J. Cell Biol. 135:1457-1470(1996) 6. Sternsdorf, T., et al; Mol. Cell Biol 19(7):5170(1996) 7. Mahajan, R. et al; Cell 88:97-107(1997) 8. Saitoh, H., et al.; J. Biol. Chem 275(9): 6252-6258(2000) 9. Mao, Y., et al.; J. Biol. Chem. 275(34):26066-26073(2000) 10. Mao, Y., et al; PNAS 97(8):4046-4051 (2000) 11. Kinoshita, Y., et al. J. Biol. Chem. 276 (9): 6656-6665 (2001) 12. Vancurova, I., et al. J. Biol. Chem. 276(26):19746-19752(2001) 13. Minty, A., et al. J. Biol. Chem. 275 (46): 36316-36323(2000) 14. Kurtzman, A., et al. PNAS 98(10):5602-5607(2001) 15. Poukka, et al. PNAS 97(26):14145-14150 (2000) 16. Tse, W., et al. J. Biol. Chem. 276 (26): 23974-23985 (2001)

Additional Info

Recognizes the unconjugated (~17kD) form of human GMP1 (SUMO-1), as well as proteins covalently ligated to GMP1(e.g. RanGAP-1). Species Crossreactivity: mouse and rat