Disease relevance of RIPK4

• Transitional carcinomas of the urinary bladder were examined immunohistochemically for keratin proteins with the use of polyclonal antiserum (TK, 41-65 kDa) and 3 monoclonal antibodies (KL 1, 55-57 kDa; PKK 1, nos. 19, 18, 8; and K 8.12, nos. 16, 13) [1].
• Immunohistochemically, the cytoplasm of numerous cells of the squamous cell carcinoma component was stained with anti-cytokeratin (PKK 1) and the cytoplasmic membrane with anti-epithelial membrane antigen (EMA) [2].

High impact information on RIPK4

• Protein kinase C-associated kinase (PKK, also known as RIP4/DIK) activates NFkappaB when overexpressed in cell lines and is required for keratinocyte differentiation in vivo [3].
• Catalytically inactive PKK mutants that block phorbol ester-induced NFkappaB activation do not interfere with, but unexpectedly enhance, the activation of NFkappaB by these two mitogen-activated protein kinase kinase kinases [3].
• The human homolog of PKK has over 90% identity to its murine counterpart, has been localized to chromosome 21q22.3, and is identical to the PKCdelta-interacting kinase, DIK (Bahr, C., Rohwer, A., Stempka, L., Rincke, G., Marks, F., and Gschwendt, M. (2000) J. Biol. Chem. 275, 36350-36357) [4].
• Expression of DIK at the mRNA and protein level could be demonstrated in several cell lines [5].
• DIK was shown to exhibit protein kinase activity toward autophosphorylation and substrate phosphorylation [5].

Biological context of RIPK4

• A novel serine/threonine kinase, termed DIK, was cloned using the yeast two-hybrid system to screen a cDNA library from the human keratinocyte cell line HaCaT with the catalytic domain of rat protein kinase Cdelta (PKCdelta(cat)) cDNA as bait [5].

Anatomical context of RIPK4

• Here we explore the consequences of a null mutation in PKK with respect to the generation of peripheral B cell lineages and the activation of NFkappaB [6].
• Intercalated duct cells of normal salivary glands reacted with RPN 1164, RPN 1165, K 4.62 and K 8.13 monoclonal antibodies, which indicates the presence of keratins 8 and 19; and ductal basal cells reacted with PKK 1, K 4.62 and K 8.12, suggesting nos [7].

Associations of RIPK4 with chemical compounds

• Inspection for signature repeats in ncamp-1 and comparisons with histone-like peptides from different species indicated the presence of multiple lysine based motifs composed of AKKA or PKK repeats [8].
• PKK clotting activity as well as the activity by a chromogenic substrate method (Chromozym PK) was less then 0.01 U/ml [9].

References