| Purification and Quality Control | HMG1 was purified from calf thymus using several steps of conventional and FPLC chromatography. | | Unit Definition (Activity) | 1 unit equals 1 nanogram of purified protein. 10-100 units are required for a gel mobility shift assay in a 20µl reaction to super-shift TBP-DNA complex, 50-500 units are required for a reconstituted transcription assay and 100 units are sufficient for a protein-protein interaction assay. | | Applications | HMG1 has been applied in in vitro transcription assays, DNA-protein and protein-protein interaction assays. | | Formulation and Storage | The protein is in 20mM Tris-HCl pH7.9,100mM NaCl, 0.2mM EDTA, 1mM DTT and 20% glycerol. Stored at -70°C before use. Avoid repeated freeze thaw cycles. | | Background | High mobility group 1 (HMG1) is a 26 kDa highly conserved non-sequence-specific DNA-binding nuclear protein (1). Mammalian HMG1 has two homologous DNA-binding domains HMG boxes, A and B (each of 80–90 amino-acid residues), linked by a short basic region to an acidic C-terminal domain containing 30 consecutive Asp and Glu residues (2). HMG1 has been implicated in a number of fundamental biological processes including transcription, replication and recombination, in which it plays a role in manipulating DNA structure by bending, looping, compaction or unwinding, or by directly contacting with distinct cellular proteins (3-5). HMG-1 can act as a repressor, by interacting with TBP to block pre-initiation complex formation (6, 7) or as an activator, by facilitating the binding of various transcription factors to their cognate DNA sequences (8, 9). Most recently, it was discovered that HMG-1 is a late mediator of delayed endotoxin lethality by activating downstream cytokine release (10). | | References | 1. Bianchi, M.E., et al., (1989) Science 243, 1056-1059
2. Bustin, M., et al., (1990) Biochim. Biophys. Acta 1049, 231-243
3. Zappavigna, V., et al., (1996) EMBO J. 15, 4981-4991
4. Ge, H., et al., (1994) J. Biol. Chem. 269, 17136-17140
5. Zlatanova, Y. et al., (1998) FASEB J. 12, 421-431
6. Stelzer, G., et al., (1994) Mol. Cell. Biol. 14, 4712-4721
7. Lu, W., et al., J Biol Chem 2000 Nov 10;275(45):35006-12
8. Jayaraman, L., et al., (1998) Genes Dev. 12, 462-472
9. Onate, S., et al., (1994) Mol. Cell. Biol. 14, 3376-3391
10. Yang, H., et al., (2001) Shock 15, 247-253 | | Image of SDS-PAGE /Western-blot | |
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