MDM2 mediates ubiquitination of p53/TP53, leading to its degration by the proteasome. MDM2 inhibits p53/TP53- and p73/TP73-mediated cell cycle arrest and apoptosis by binding to their respective transcriptional activation domains. MDM2 also acts as an ubiquitin ligase towards itself and ARRB1, permits the nuclear export of TP53/p53, and promotes proteasome-dependent ubiquitin-independent degradation of retinoblastoma RB1 protein.
This peptide is a fluorogenic substrate for trypsin, a peptidase S1 family members that cleaves at Arg-Xaa and Lys-Xaa sites within proteins. The peptide is labeled with rhodamine 110, a highly fluororescent dye upon substrate cleavage (Abs/Em = 497/520 nm).
BTK (Tyrosine-protein kinase BTK) is a tyrosine kinase that plays a crucial role in B-cell ontogeny. Defects in BTK are the cause of X-linked agammaglobulinemia (XLA) also known as X-linked agammaglobulinemia type 1 (AGMX1) or immunodeficiency type 1 (IMD1). XLA is a humoral immunodeficiency disease which results in developmental defects in the maturation pathway of B-cells. Affected boys have normal levels of pre-B-cells in their bone marrow but virtually no circulating mature B-lymphocytes.