Structural and phylogenetic characterization of human SLURP-1, the first secreted mammalian member of the Ly-6/uPAR protein superfamily

Protein Sci. 1999 Apr;8(4):810-9. doi: 10.1110/ps.8.4.810.


Members of the Ly-6/uPAR protein family share one or several repeat units of the Ly-6/uPAR domain that is defined by a distinct disulfide bonding pattern between 8 or 10 cysteine residues. The Ly-6/uPAR protein family can be divided into two subfamilies. One comprises GPI-anchored glycoprotein receptors with 10 cysteine residues. The other subfamily includes the secreted single-domain snake and frog cytotoxins, and differs significantly in that its members generally possess only eight cysteines and no GPI-anchoring signal sequence. We report the purification and structural characterization of human SLURP-1 (secreted mammalian Ly-6/uPAR related protein 1) from blood and urine peptide libraries. SLURP-1 is encoded by the ARS (component B)-81/s locus, and appears to be the first mammalian member of the Ly-6/uPAR family lacking a GPI-anchoring signal sequence. A phylogenetic analysis based on the SLURP-1 primary protein structure revealed a closer relationship to the subfamily of cytotoxins. Since the SLURP-1 gene maps to the same chromosomal region as several members of the Ly-6/uPAR subfamily of glycoprotein receptors, it is suggested that both biologically distinct subfamilies might have co-evolved from local chromosomal duplication events.

MeSH terms

  • Animals
  • Antigens, Ly / blood
  • Antigens, Ly / chemistry*
  • Antigens, Ly / urine
  • Anura
  • Cytotoxins / chemistry
  • Humans
  • Mass Spectrometry
  • Peptide Library
  • Phylogeny*
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Snakes
  • Time Factors
  • Urokinase-Type Plasminogen Activator / blood
  • Urokinase-Type Plasminogen Activator / chemistry*
  • Urokinase-Type Plasminogen Activator / urine


  • Antigens, Ly
  • Cytotoxins
  • Peptide Library
  • SLURP1 protein, human
  • Urokinase-Type Plasminogen Activator