Slob

The family name Slob comes from slow-as-molasses phenotypes in Drosophila genetics, and the single human member is PXK, PX domain-containing kinase-like protein. PXK pairs an N-terminal PX (phox homology) domain, which binds phosphoinositides and targets the protein to endosomal membranes, with a C-terminal kinase-like domain whose catalytic motifs are degenerate, so PXK is generally treated as a pseudokinase. Reported observations place it in cell survival, proliferation and cytoskeletal organization, with altered expression described in tumor samples and in neuronal tissue. Because substrates and mechanism are undefined, recombinant PXK is used for lipid-binding studies, protein interaction mapping and antibody generation.