The BSP30 salivary proteins from cattle, LUNX/PLUNC and von Ebner's minor salivary gland protein are members of the PSP/LBP superfamily of proteins

Biochim Biophys Acta. 2002 Dec 12;1579(2-3):92-100. doi: 10.1016/s0167-4781(02)00508-0.


Saliva influences rumen function in cattle, yet the biochemical role for most of the bovine salivary proteins (BSPs) has yet to be established. Two cDNAs (BSP30a and BSP30b) from bovine parotid salivary gland were cloned and sequenced, each coding for alternate forms of a prominent protein in bovine saliva. The BSP30 cDNAs share 96% sequence identity with each other at the DNA level and 83% at the amino acid level, and appear to arise from separate genes. The predicted BSP30a and BSP30b proteins share 26-36% amino acid identity with parotid secretory protein (PSP) from mouse, rat and human. BSP30 and PSP are in turn more distantly related to a wider group of proteins that includes lung-specific X protein, also known as palate, lung, and nasal epithelium clone (LUNX/PLUNC), von Ebner's minor salivary gland protein (VEMSGP), bactericidal permeability increasing protein (BPI), lipopolysaccharide binding protein (LBP), cholesteryl ester transfer protein (CETP), and the putative olfactory ligand-binding proteins RYA3 and RY2G5. Bovine cDNAs encoding homologs of LUNX/PLUNC and VEMSGP were isolated and sequenced. Northern blot analysis showed that LUNX/PLUNC, BSP30 and VEMSGP are expressed in bovine salivary tissue and airways, and that they have non-identical patterns of expression in these tissues. The expression of both BSP30a and BSP30b is restricted to salivary tissue, but within this tissue they have distinct patterns of expression. The proximity of the human genes coding for the PSP/LBP superfamily on HSA20q11.2, their similar amino acid sequence, and common exon segmentation strongly suggest that these genes evolved from a common ancestral gene. Furthermore, they imply that the BSP30a and BSP30b proteins may have a function in common with other members of this gene family.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Blotting, Northern
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Cattle
  • Cloning, Molecular
  • DNA, Complementary / biosynthesis
  • DNA, Complementary / chemistry
  • Gene Expression
  • Glycoproteins / chemistry
  • Glycoproteins / genetics
  • Lipocalin 1
  • Molecular Sequence Data
  • Multigene Family*
  • Parotid Gland / metabolism*
  • Phosphoproteins / chemistry
  • Phosphoproteins / genetics
  • RNA / analysis
  • Salivary Glands, Minor / metabolism*
  • Salivary Proteins and Peptides / biosynthesis
  • Salivary Proteins and Peptides / chemistry
  • Salivary Proteins and Peptides / genetics*
  • Sequence Alignment
  • Sequence Homology, Nucleic Acid
  • Terminology as Topic*


  • BPIFA1 protein, human
  • Bpifa1 protein, rat
  • Bpifa2 protein, mouse
  • Bpifa2 protein, rat
  • Carrier Proteins
  • DNA, Complementary
  • Glycoproteins
  • LCN1 protein, human
  • Lipocalin 1
  • Phosphoproteins
  • Salivary Proteins and Peptides
  • Vegp1 protein, rat
  • RNA

Associated data

  • GENBANK/U79413
  • GENBANK/U79414