P RB (Retinoblastoma protein)

• Species: Human
• Expression Host: Baculovirus-insect cell
• Tag: His-tag
• Purity: 95%
• Molecular Weight: 107.5 kDa.
• Gene Accession Number: NM_000321.

Purification and Quality Control
The His-tag recombinant protein is purified by affinity chromatography in combination with FPLC columns.
The purified pRB is greater than 95% homogeneous based on SDS-PAGE analysis.

Unit Definition (Activity)
1 unit equals 1 nanogram of purified protein. 1 unit is sufficient for a gel mobility shift assay in a 20 µl reaction; 50 units are sufficient for reconstituted transcription assay and 100 units are sufficient for a protein-protein interaction assay.

Applications
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.

Formulation and Storage
Protein is stored in 20 mM Tris-Cl (pH 8.0), 20% Glycerol, 100 mM KCl, 1 mM DTT and 0.2 mM EDTA buffer and kept at -80°C. Avoid repeatly freeze thaw cycles.

Synonym
OSRC; p105-Rb; pp110; pRb; RB.

Protein Sequence
TPRKTAATAA AAAAEPPAPP PPPPPEEDPE QDSGPEDLPL VRLEFEETEE PDFTALCQKL
KIPDHVRERA WLTWEKVSSV DGVLGGYIQK KKELWGICIF IAAVDLDEMS FTFTELQKNI
EISVHKFFNL LKEIDTSTKV DNAMSRLLKK YDVLFALFSK LERTCELIYL TQPSSSISTE
INSALVLKVS WITFLLAKGE VLQMEDDLVI SFQLMLCVLD YFIKLSPPML LKEPYKTAVI
PINGSPRTPR RGQNRSARIA KQLENDTRII EVLCKEHECN IDEVKNVYFK NFIPFMNSLG
LVTSNGLPEV ENLSKRYEEI YLKNKDLDAR LFLDHDKTLQ TDSIDSFETQ RTPRKSNLDE
EVNVIPPHTP VRTVMNTIQQ LMMILNSASD QPSENLISYF NNCTVNPKES ILKRVKDIGY
IFKEKFAKAV GQGCVEIGSQ RYKLGVRLYY RVMESMLKSE EERLSIQNFS KLLNDNIFHM
SLLACALEVV MATYSRSTSQ NLDSGTDLSF PWILNVLNLK AFDFYKVIES FIKAEGNLTR
EMIKHLERCE HRIMESLAWL SDSPLFDLIK QSKDREGPTD HLESACPLNL PLQNNHTAAD
MYLSPVRSPK KKGSTTRVNS TANAETQATS AFQTQKPLKS TSLSLFYKKV YRLAYLRLNT
LCERLLSEHP ELEHIIWTLF QHTLQNEYEL MRDRHLDQIM MCSMYGICKV KNIDLKFKII
VTAYKDLPHA VQETFKRVLI KEEEYDSIIV FYNSVFMQRL KTNILQYAST RPPTLSPIPH
IPRSPYKFPS SPLRIPGGNI YISPLKSPYK ISEGLPTPTK MTPRSRILVS IGESFGTSEK
FQKINQMVCN SDRVLKRSAE GSNPPKPLKK LRFDIEGSDE ADGSKHLPGE SKFQQKLAEM
TSTRTRMQKQ KMNDSMDTSN KEEK

Background
pRB, the product of retinoblastoma susceptibility gene RB-1, is one of the best-studied tumor suppressor gene products. At least two other pRB-related proteins, p107 and p130, have been identified and characterized. Mutations in RB-1 gene are often associated with the occurrence of various tumors (1-3). The activity of pRB is regulated through phosphorylation in a cell cycle-dependent manner. The hyperphosphorylated RB protein usually associates with the cell nucleus and binds transcription factors of the E2F family (4, 5). pRB represses transcription of its target genes, such as cdc2, cyclin A, and oncogene c-Myc, c-Fos through the binding with E2F factors and thereby regulating cell proliferation (6).

Image of SDS-PAGE /Western-blot