STE20-related pseudokinase

STE20-related kinase adapter protein alpha (STRADA) is a catalytically inactive pseudokinase protein located on human chromosome 17q23.3 (1). In its association with calcium binding protein 39 (CAB39), it regulates the activity of Serine/Threonine Kinase 11 (STK11/LKB1) tumor suppressors (2). LKB1 was discovered in 1988 and ever since then extensive research has been conducted in understanding how this protein might be regulated. It was reported that LKB1 mediates its cellular functions through interactions with a number of proteins including CAB39 and STRADalpha (3). CAB39 and STRADalpha are identified as key proteins required for the growth suppressive function of LKB1. Studies reported that association of STRADA with ATP or CAB39 is essential for LKB1 activation and, STRADA is also required for LKB1-induced G1 cell cycle arrest (4).

It has been deduced that STRADA interacts with CAB39 via its C-terminal Trp-Glu-Phe residues (WEF motif) and any mutations in these residues abolishes this interaction. Although such STRADA mutants are unable to interact directly with CAB39, they can still form a heterotrimeric complex with LKB1 and CAB39 (5). This demonstrates that STRADA possesses multiple interaction sites for CAB39 and LKB1 that are separate from the WEF motif. Other studies have identified that deletion of 180 C-terminal residues of STRADA causes severe human developmental and epileptic syndrome termed polyhydraminos, megalencephaly, and symptomatic epilepsy (PMSE) syndrome (6). STRADA is approximately a 58kDa protein (431 amino acids).

The STRADA antibodies were generated against purified STE20-related kinase adapter protein alpha. STRADA antibodies are affinity purified over immobilized antigen based chromatography, and the purified immunoglobulin is stabilized in antibody stabilization buffer. FabGennix Int. Inc. will also provide limited quantities of antigenic blocking protein for STRADA antibody. Antibodies to STRADA (STRADA-101AP) will label ~57.1kDa protein in Western blot positive control samples for STRADA and several other tissues. FabGennix Inc. will also conjugate antibodies with secondary enzymes (alk-Pase or HRP) or fluorescent probes upon request at nominal cost.

For research use only, not for diagnostic or therapeutic use.