STE20-related kinase adapter protein beta; STRAD beta; amyotrophic lateral sclerosis 2 chromosomal region candidate gene 2 protein; CALS-21; ILP-interacting protein; Pseudokinase ALS2CR2 (STRADB, ALS2CR2, ILPIP, PRO1038)

Function

• pseudokinase which, in complex with CAB39/MO25 (CAB39/MO25alpha or CAB39L/MO25beta), binds to & activates STK11/LKB1
• adopts a closed conformation typical of active protein kinases & binds STK11/LKB1 as a pseudosubstrate, promoting conformational change of STK11/LKB1 in an active conformation
• component of a trimeric complex composed of STK11/LKB1, STRAD (STRADA or STRADB) & CAB39/MO25 (CAB39/MO25alpha or CAB39L/MO25beta)
  • the complex tethers STK11/LKB1 in the cytoplasm & stimulates its catalytic activity
• interacts with BIRC4/XIAP
  • STRADB & BIRC4 are likely to coexist in a complex with TAK1, TRAF6, TAB1 & TAB2

Structure

• the protein kinase domain is predicted to be catalytically inactive
  • Ser-184 is present instead of the conserved Asp which is expected to be an active site residue
• belongs to the protein kinase superfamily, STE Ser/Thr protein kinase family, STE20 subfamily contains 1 protein kinase domain

Compartment

nucleus. cytoplasm

Alternative splicing

named isoforms=3

Expression

• highly expressed in heart, skeletal muscle, testis, liver & colon

More general terms

• nuclear protein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=55437
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:55437
• OMIM: https://mirror.omim.org/entry/607333
• UniProt: http://www.uniprot.org/uniprot/Q9C0K7.html