IK Cytokine, Down Regulator Of HLA II (IK)

IK is in fact part of a larger gene encoding a 557-amino acid protein that is 98% identical to the mouse sequence and contains an extensive stretch of arg-glu-asp (RED) repeats. Notably, the codon usage in the RED repeat is varied, suggesting the sequence is not a result of repetitive duplication. RE repeats are found in atrophin-1, and RD repeats are found in RD. RED is expressed in both bacterial and mammalian cells as an 80-kD protein. Sequence analysis predicted and immunofluorescence analysis demonstrated that RED is localized to nuclear dots similar to the expression pattern of PML bodies; however, RED does not colocalize with PML or coilin (COIL) and appears to be sequestered from the nucleoplasm.