This antigen is a type I membrane protein with 1 extracellular F5/8 type C domain. Signal peptide: (1-20); glycosylated extracellular region: (21-416); TM (417-439); intracellular Y-phospho-IDRs + kinase domain (440-913). The soluble urine/milk/blood plasma form does not have signals cward of R341.

Human discoidin domain receptor tyrosine kinase 1 (#DDR1:p, #CD167:p)―HPA mRNA tissue & cell type distributions paired with GPMDB protein tissue & cell type tabbulations. #proteomics #sources_sinks

The Y+phosphoryl pattern associated with the intracellular region show multiple acceptors, some potentially auto-phosphorylated.
The retention of the "discoidin" in the name is a bit of historical goofiness: a domain similar to the N-terminal region of this protein was initially found on a slime mold (Dictyostelium discoideum) adhesion protein with the rather on-the-nose, dopey name discoidin.