SH3BP5 Proteins and Enzymes

SH3BP5 (SH3 domain binding protein 5) binds to the SH3 domain of Bruton tyrosine kinase (BTK), a cytoplasmic tyrosine kinase crucial for the maturation of B-lineage cells. It inhibits the auto- and transphosphorylation activity of BTK and negatively regulates BTK-related cytoplasmic signaling in B-cells. SH3BP5 also interacts with JNK. The interaction with JNK occurs through a mitogen-activated protein KIM (kinase interaction motif) in a region distinct from the Bruton's tyrosine kinase-binding domain.