CDKN1B
GeneName
CDKN1B
Summary
CDKN1B, also known as p27, Kip1, or p27Kip1, is a 22 kDa cyclin-dependent kinase inhibitor that plays a vital role in regulating the cell cycle, particularly at the G1/S transition. It is expressed in various tissues, including the heart and epithelial cells, and is localised in multiple cellular compartments such as the nucleus, cytoplasm, and centrosome. CDKN1B functions by binding to cyclin-CDK complexes, inhibiting their activity, which leads to cell cycle arrest and influences processes such as cellular senescence, apoptosis, and tissue development. Additionally, it has roles in the regulation of autophagic cell death and response to DNA damage, highlighting its importance in maintaining cellular homeostasis.
Importance
CDKN1B is relevant to: - Cancer research due to its role in cell cycle regulation and its potential as a tumour suppressor. - Developmental biology, particularly in heart and epithelial tissue development, where it influences cell proliferation and differentiation. - Neurobiology, as it has been implicated in processes such as sensory perception and neuronal development. - Understanding the mechanisms of ageing and cellular senescence, given its involvement in regulating cellular responses to stress and growth factors.
Top Products
For researchers investigating CDKN1B, we highly recommend the top-selling recombinant antibody, Anti-p27 KIP 1 antibody [Y236] (ab32034). This well-cited antibody has garnered 228 citations, reflecting its strong reputation in the field. It has been validated in knockout models and is suitable for a variety of applications, including Western blotting (WB), immunohistochemistry (IHC), immunocytochemistry (ICC), immunoprecipitation (IP), and flow cytometry (FC). This versatility makes it an excellent choice for those seeking reliable detection of CDKN1B across different experimental setups. The Anti-p27 KIP 1 ELISA Kit (ab113075), supported by 2 citations, is an excellent option for researchers looking to accurately measure CDKN1B levels in their samples.
Abcam Product Citation Summary
The data indicates that CDKN1B is being studied in various human cell types, particularly in the context of cancer, drug resistance, and cellular processes such as proliferation and senescence. The use of multiple applications, including Western blotting and immunohistochemistry, highlights the importance of this target in understanding disease mechanisms.
Abcam Product Citation Table
Domain
A peptide sequence containing only AA 28-79 retains substantial Kip1 cyclin A/CDK2 inhibitory activity.
Function
Important regulator of cell cycle progression. Inhibits the kinase activity of CDK2 bound to cyclin A, but has little inhibitory activity on CDK2 bound to SPDYA (PubMed:28666995). Involved in G1 arrest. Potent inhibitor of cyclin E- and cyclin A-CDK2 complexes. Forms a complex with cyclin type D-CDK4 complexes and is involved in the assembly, stability, and modulation of CCND1-CDK4 complex activation. Acts either as an inhibitor or an activator of cyclin type D-CDK4 complexes depending on its phosphorylation state and/or stoichometry.
Involvement in disease
Multiple endocrine neoplasia 4
MEN4
Multiple endocrine neoplasia (MEN) syndromes are inherited cancer syndromes of the thyroid. MEN4 is a MEN-like syndrome with a phenotypic overlap of both MEN1 and MEN2.
None
The disease is caused by variants affecting the gene represented in this entry.
Post-translational modifications
Phosphorylated; phosphorylation occurs on serine, threonine and tyrosine residues. Phosphorylation on Ser-10 is the major site of phosphorylation in resting cells, takes place at the G(0)-G(1) phase and leads to protein stability. Phosphorylation on other sites is greatly enhanced by mitogens, growth factors, cMYC and in certain cancer cell lines. The phosphorylated form found in the cytoplasm is inactivate. Phosphorylation on Thr-198 is required for interaction with 14-3-3 proteins. Phosphorylation on Thr-187, by CDK1 and CDK2 leads to protein ubiquitination and proteasomal degradation. Tyrosine phosphorylation promotes this process. Phosphorylation by PKB/AKT1 can be suppressed by LY294002, an inhibitor of the catalytic subunit of PI3K. Phosphorylation on Tyr-88 and Tyr-89 has no effect on binding CDK2, but is required for binding CDK4. Dephosphorylated on tyrosine residues by G-CSF.
Ubiquitinated; in the cytoplasm by the KPC complex (composed of RNF123/KPC1 and UBAC1/KPC2) and, in the nucleus, by SCF(SKP2). The latter requires prior phosphorylation on Thr-187. Ubiquitinated; by a TRIM21-containing SCF(SKP2)-like complex; leads to its degradation.
Subject to degradation in the lysosome. Interaction with SNX6 promotes lysosomal degradation (By similarity).
Sequence Similarities
Belongs to the CDI family.
Tissue Specificity
Expressed in kidney (at protein level) (PubMed:15509543). Expressed in all tissues tested (PubMed:8033212). Highest levels in skeletal muscle, lowest in liver and kidney (PubMed:8033212).
Cellular localization
- Nucleus
- Cytoplasm
- Endosome
- Nuclear and cytoplasmic in quiescent cells. AKT- or RSK-mediated phosphorylation on Thr-198, binds 14-3-3, translocates to the cytoplasm and promotes cell cycle progression. Mitogen-activated UHMK1 phosphorylation on Ser-10 also results in translocation to the cytoplasm and cell cycle progression. Phosphorylation on Ser-10 facilitates nuclear export. Translocates to the nucleus on phosphorylation of Tyr-88 and Tyr-89. Colocalizes at the endosome with SNX6; this leads to lysosomal degradation (By similarity).
Alternative names
KIP1, p27, CDKN1B, Cyclin-dependent kinase inhibitor 1B, Cyclin-dependent kinase inhibitor p27, p27Kip1