Synthetic peptide (the amino acid sequence is considered to be commercially sensitive) within Human p21 aa 1-100. The exact sequence is proprietary.
WB: MCF7, HeLa, HEK293, HUVEC, LnCaP, U87 MG or 293T cell lysates.
IHC-P: Human cervical carcinoma or papillary carcinoma of thyroid gland tissues.
ICC/IF: MCF-7 cells.
Flow Cyt: HeLa cells.
IP: HEK293 cell lysate.
A trial size is available to purchase for this antibody.
Produced using Abcam's RabMAb® technology. RabMAb® technology is covered by the following U.S. Patents, No. 5, 675, 063 and/or 7, 429, 487.
We are constantly working hard to ensure we provide our customers with best in class antibodies. As a result of this work we are pleased to now offer this antibody in purified format. We are in the process of updating our datasheets. The purified format is designated 'PUR' on our product labels. If you have any questions regarding this update, please contact our Scientific Support team.
This product is a recombinant rabbit monoclonal antibody.
Storage instructionsShipped at 4°C. Store at +4°C short term (1-2 weeks). Upon delivery aliquot. Store at -20°C. Stable for 12 months at -20°C.
FunctionMay be the important intermediate by which p53/TP53 mediates its role as an inhibitor of cellular proliferation in response to DNA damage. Binds to and inhibits cyclin-dependent kinase activity, preventing phosphorylation of critical cyclin-dependent kinase substrates and blocking cell cycle progression. Functions in the nuclear localization and assembly of cyclin D-CDK4 complex and promotes its kinase activity towards RB1. At higher stoichiometric ratios, inhibits the kinase activity of the cyclin D-CDK4 complex.
Tissue specificityExpressed in all adult human tissues, with 5-fold lower levels observed in the brain.
Sequence similaritiesBelongs to the CDI family.
DomainThe PIP-box K+4 motif mediates both the interaction with PCNA and the recuitment of the DCX(DTL) complex: while the PIP-box interacts with PCNA, the presence of the K+4 submotif, recruits the DCX(DTL) complex, leading to its ubiquitination. The C-terminal is required for nuclear localization of the cyclin D-CDK4 complex.
Post-translational modificationsPhosphorylation of Thr-145 by Akt or of Ser-146 by PKC impairs binding to PCNA. Phosphorylation at Ser-114 by GSK3-beta enhances ubiquitination by the DCX(DTL) complex. Ubiquitinated by MKRN1; leading to polyubiquitination and 26S proteasome-dependent degradation. Ubiquitinated by the DCX(DTL) complex, also named CRL4(CDT2) complex, leading to its degradation during S phase or following UV irradiation. Ubiquitination by the DCX(DTL) complex is essential to control replication licensing and is PCNA-dependent: interacts with PCNA via its PIP-box, while the presence of the containing the 'K+4' motif in the PIP box, recruit the DCX(DTL) complex, leading to its degradation.
Immunocytochemistry/Immunofluorescence analysis of MCF7 cells labelling p21 with purified ab109520 at 1/1000. Cells were fixed with 4% paraformaldehyde and permeabilized with 0.1% Triton X-100. ab150077, an Alexa Fluor® 488-conjugated goat anti-rabbit IgG (1/500) was used as the secondary antibody. DAPI (blue) was used as the nuclear counterstain. ab7291, a mouse anti-tubulin (1/1000) and ab150120, an Alexa Fluor® 594-conjugated goat anti-mouse IgG (1/500) were also used.
Control 1: primary antibody (1/1000) and secondary antibody, ab150120, an Alexa Fluor® 594-conjugated goat anti-mouse IgG (1/500).
Control 2: ab7291 (1/1000) and secondary antibody, ab150077, an Alexa Fluor® 488-conjugated goat anti-rabbit IgG (1/500).
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) analysis of human thyroid carcinoma tissue labelling p21 with purified ab109520 at 1/100. Heat mediated antigen retrieval was performed using Tris/EDTA buffer pH 9. ab97051, a HRP-conjugated goat anti-rabbit IgG (H+L) was used as the secondary antibody (1/500). Negative control using PBS instead of primary antibody. Counterstained with hematoxylin.
Western blot - Anti-p21 antibody [EPR362] (ab109520)
All lanes : Anti-p21 antibody [EPR362] (ab109520) at 1/2000 dilution (purified)
Lane 1 : MCF7 cell lysate Lane 2 : HEK293 cell lysate Lane 3 : U87-MG cell lysate
Lysates/proteins at 20 µg per lane.
Secondary Peroxidase-conjugated goat anti-rabbit IgG, (H+L) at 1/1000 dilution
Predicted band size : 21 kDa Observed band size : 21 kDa
Overlay histogram showing HeLa cells stained with unpurified ab109520 (red line). The cells were fixed with 80% methanol (5 min) then permeabilized with 0.1% PBS-Tween 20 for 20 min. The cells were then incubated in 1x PBS / 10% normal goat serum / 0.3M glycine to block non-specific protein-protein interactions followed by the antibody (unpurified ab109520, 1/100) for 30 min at 22ºC. The secondary antibody used was Alexa Fluor® 488 goat anti-rabbit IgG (H&L) (ab150081) at 1/2000 dilution for 30 min at 22ºC. Isotype control antibody (black line) was rabbit IgG (monoclonal) (ab172730, 1μg/1x106 cells) used under the same conditions. Unlabelled sample (blue line) was also used as a control.
Acquisition of >5,000 events were collected using a 20mW Argon ion laser (488nm) and 525/30 bandpass filter.
References for Anti-p21 antibody [EPR362] (ab109520)
This product has been referenced in:
Gao K et al. Deregulated WWOX is involved in a negative feedback loop with microRNA-214-3p in osteosarcoma. Int J Mol MedN/A:N/A (2016).
Read more (PubMed: 27840941) »
Chen Y et al. Hydroquinone-induced malignant transformation of TK6 cells by facilitating SIRT1-mediated p53 degradation and up-regulating KRAS. Toxicol Lett259:133-42 (2016).
Read more (PubMed: 27515134) »