Expected species cross reactivity based on sequence homology: Mouse (86%), Rat (88%)

This gene encodes a protein that belongs to the serine/threonine protein kinase STE20 subfamily. One of the active site residues in the protein kinase domain of this protein is altered, and it is thus a pseudokinase. This protein is a component of a complex involved in the activation of serine/threonine kinase 11, a master kinase that regulates cell polarity and energy-generating metabolism. This complex regulates the relocation of this kinase from the nucleus to the cytoplasm, and it is essential for G1 cell cycle arrest mediated by this kinase. The protein encoded by this gene can also interact with the X chromosome-linked inhibitor of apoptosis protein, and this interaction enhances the anti-apoptotic activity of this protein via the JNK1 signal transduction pathway. Two pseudogenes, located on chromosomes 1 and 7, have been found for this gene. [provided by RefSeq]

ILPIP (ILP-interacting protein) has recently been shown to interact with XIAP, a member of the IAP (Inhibitor of Apoptosis) protein family. Together, these two proteins synergistically activate the TAK1/JNK1 signal transduction pathway, which acts to protect against the interleukin-1beta converting enzyme of Fas-induced apotosis. This protein was independently isolated and characterized as polyploidy-associated protein kinase (PAPK), a member of the Ste20/germinal center kinase family that modulates cytoskeletal organization and cell survival, suggesting that its protective role may be a function of its kinase activity. Although two mRNA sequences have been isolated, only the shorter isoform has been observed.

ILPIP (ILP-interacting protein) has recently been shown to interact with XIAP, a member of the IAP (Inhibitor of Apoptosis) protein family. Together, these two proteins synergistically activate the TAK1/JNK1 signal transduction pathway, which acts to protect against the interleukin-1b converting enzyme of Fas-induced apotosis. This protein was independently isolated and characterized as polyploidy-associated protein kinase (PAPK), a member of the Ste20/germinal center kinase family that modulates cytoskeletal organization and cell survival, suggesting that its protective role may be a function of its kinase activity. Although two mRNA sequences have been isolated, only the shorter isoform has been observed.