DOK proteins are enzymatically inert adaptor or scaffolding proteins. Rather than catalysing reactions, they provide a docking platform for the assembly of multimolecular signalling complexes. DOK3 follows this pattern and is described as a negative regulator of JNK signalling in B-cells, an effect that depends on its interaction with INPP5D (also called SHIP1). It may also modulate the function of ABL1.

The DOK3 protein belongs to the DOK family, Type A subfamily, and is classed by HGNC in the docking protein family. UniProt records its subcellular location as the cytoplasm and the cell membrane, and NCBI Gene lists it as located in the plasma membrane. The mouse and rat orthologues are both named Dok3, which allows the same target to be studied in common rodent models.

NCBI Gene summary text predicts that the DOK3 gene enables signalling adaptor activity and is involved in Ras protein signal transduction. DOK3 has also been implicated in colorectal adenocarcinoma. Related family members, including DOK1, DOK2, DOK6 and DOK7, share the adaptor role but are separate gene products, so it is worth confirming which DOK protein a given experiment addresses when selecting a DOK3 antibody, DOK3 ELISA kit or recombinant DOK3 protein.