CDKN1B
CDKN1B (cyclin dependent kinase inhibitor 1B, also known as KIP1 and P27KIP1) is an important regulator of cell cycle progression. It restrains cyclin-CDK complexes to control the G1 phase, and its loss is linked to multiple endocrine neoplasia type IV. Browse Assay Genie's current range of CDKN1B research reagents below, or read on for the biology behind the target.
CDKN1B is a cyclin-dependent kinase inhibitor that acts as an important regulator of cell cycle progression and is involved in G1 arrest. It is a potent inhibitor of cyclin E- and cyclin A-CDK2 complexes. It inhibits CDK2 bound to cyclin A, but has little inhibitory activity on CDK2 bound to SPDYA. The protein binds to and prevents the activation of cyclin E-CDK2 or cyclin D-CDK4 complexes, and so controls progression through G1.
Its relationship with cyclin D-CDK4 is more nuanced. CDKN1B forms a complex with cyclin type D-CDK4 and is involved in the assembly, stability and modulation of CCND1-CDK4 complex activation. Depending on its phosphorylation state and/or stoichiometry, it can act as either an inhibitor or an activator of these complexes. The protein localises to the nucleus, cytoplasm and endosome, and belongs to the CDI family. The CDKN1B gene encodes a protein that shares limited similarity with the CDK inhibitor CDKN1A (p21).
CDKN1B levels are controlled by degradation. CDK-dependent phosphorylation of the protein, followed by ubiquitination by SCF complexes, triggers its destruction, and this is required for cells to move from quiescence to the proliferative state. Mutations in the gene are associated with multiple endocrine neoplasia type IV (MEN4). The protein was formerly named cyclin-dependent kinase inhibitor 1B (p27, Kip1), which explains the aliases KIP1 and P27KIP1. A mouse ortholog, Cdkn1b, is also annotated.
CDKN1B restrains cyclin E- and cyclin A-CDK2 complexes and contributes to G1 arrest, making it a central readout in cell cycle studies.
Phosphorylation-dependent ubiquitination of CDKN1B by SCF complexes is required for the transition from quiescence to the proliferative state.
CDKN1B can inhibit or activate cyclin D-CDK4 complexes depending on phosphorylation and stoichiometry, offering a model for studying CDK complex assembly.
Mutations in the CDKN1B gene are associated with multiple endocrine neoplasia type IV (MEN4), linking the protein to tumour biology.
CDKN1B is an important regulator of cell cycle progression. It inhibits cyclin E- and cyclin A-CDK2 complexes and prevents activation of cyclin D-CDK4 complexes, controlling the cell cycle at G1. Depending on its phosphorylation state and stoichiometry, it can also activate cyclin D-CDK4.
CDKN1B is also called KIP1 and P27KIP1. Its previous name was cyclin-dependent kinase inhibitor 1B (p27, Kip1). HGNC places it in the cyclin dependent kinase inhibitor 1 family, and UniProt lists it in the CDI family alongside CDKN1A (p21).
Mutations in CDKN1B are associated with multiple endocrine neoplasia type IV (MEN4). The mouse ortholog is Cdkn1b. Check the datasheet of any product for its validated reactivity.
Other cyclin-dependent kinase inhibitors and cell cycle regulators with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P46527; product specifications from Assay Genie datasheets.