MAP3K21
MAP3K21 (mitogen-activated protein kinase kinase kinase 21, also known as MLK4 and KIAA1804) is a serine/threonine protein kinase of the mixed lineage kinase family. It acts as a negative regulator of TLR4 signalling. Browse Assay Genie's current range of MAP3K21 research reagents below, or read on for the biology behind the target.
MAP3K21 is a negative regulator of TLR4 signalling. UniProt annotation states that it does not activate the JNK1/MAPK8, p38/MAPK14 or ERK2/MAPK1 pathways, which sets it apart from what the name might suggest for a kinase at the top of a MAP kinase cascade. Gene-level predictions describe it as enabling JUN kinase kinase kinase activity and protein homodimerisation activity, and as being involved in protein phosphorylation and signal transduction.
The MAP3K21 protein belongs to the protein kinase superfamily, in the STE Ser/Thr protein kinase family and the MAP kinase kinase kinase subfamily. It carries the enzyme classification EC 2.7.11.25. HGNC places the MAP3K21 gene in the groups for mitogen-activated protein kinase kinase kinases, the mixed lineage kinase family and SH3 domain-containing proteins. The protein is predicted to be active in the cytoplasm, although UniProt does not currently annotate a subcellular location. The mouse ortholog is Map3k21.
The protein is also known as MLK4, reflecting its membership of the mixed lineage kinase family, and by the older gene identifier KIAA1804. Researchers studying MAP3K21 often examine it alongside other MAP3K family members to compare how related kinases are wired into signalling networks. Because the available functional evidence centres on restraint of TLR4 signalling and not on activation of the canonical MAPK branches, MAP3K21 is a useful subject for work on how kinase family members can diverge in function.
MAP3K21 is annotated as a negative regulator of TLR4 signalling, making it relevant to studies of how this pathway is restrained.
As a MAP kinase kinase kinase that does not activate JNK1, p38 or ERK2 pathways, it informs comparisons across the MAP3K subfamily.
MAP3K21 sits in the STE Ser/Thr kinase family and the mixed lineage kinase group, supporting work on kinase classification and function.
Predicted roles in protein phosphorylation and signal transduction make MAP3K21 a candidate for investigating intracellular signalling mechanisms.
MAP3K21 is a negative regulator of TLR4 signalling. UniProt reports that it does not activate the JNK1/MAPK8, p38/MAPK14 or ERK2/MAPK1 pathways. Gene-level predictions also link it to JUN kinase kinase kinase activity, protein homodimerisation, protein phosphorylation and signal transduction.
MAP3K21 is the approved symbol for mitogen-activated protein kinase kinase kinase 21. It is also called MLK4, after the mixed lineage kinase family, and KIAA1804. The enzyme classification is EC 2.7.11.25, and it belongs to the MAP kinase kinase kinase subfamily.
A mouse ortholog, Map3k21, is recorded for the human MAP3K21 gene. No rat ortholog is given in the data used here. For any reagent, check the datasheet of any product for its validated reactivity.
Other MAP kinase kinase kinases, mixed lineage kinases and downstream MAP2K pathway kinases with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q5TCX8; product specifications from Assay Genie datasheets.