An alternatively spliced Muc10 glycoprotein ligand for putative L-selectin binding during mouse embryonic submandibular gland morphogenesis

Arch Oral Biol. 2001 Aug;46(8):745-57. doi: 10.1016/s0003-9969(01)00027-9.

Abstract

Late-gestation (embryonic day 18; E18) mouse submandibular glands (SMG) comprise a network of large and small ducts that terminate in lumen-containing, presumptive acini (terminal buds) expressing unique, cell membrane-associated embryonic mucin. The objective here was to clone and sequence embryonic low molecular-weight SMG mucin, predict its secondary structure, and begin to investigate its possible role in SMG development. Evidence was found that: (1) embryonic low molecular-weight mucin is an alternatively spliced Muc10 gene product, 220 amino acids in size (approximately 25 kDa), rich in potential O-glycosylation sites, and variably glycosylated (approximately 40 and 68 kDa); (2) consensus secondary-structure prediction for embryonic low molecular-weight mucin is consistent with a molecule that is anchored to the plasma membrane, directly or indirectly (via a glycolipid), and has a protein core that serves as a scaffold for carbohydrate presentation; (3) embryonic L-selectin is immunolocalized to the plasma membrane region of terminal-bud epithelial cells in a pattern similar to that seen for embryonic mucin; (4) embryonic, but not adult, mucin is able to bind L-selectin and does so endogenously in E18 SMG. As the primary role of L-selectin is to mediate cell adhesion and its ligands are mucin-like glycoproteins, it is suggested that this embryonic low molecular-weight mucin be termed MucCAM.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Age Factors
  • Alternative Splicing*
  • Amino Acid Sequence
  • Animals
  • Blotting, Western
  • Cell Adhesion
  • Cell Membrane / ultrastructure
  • Cloning, Molecular
  • Epithelial Cells / ultrastructure
  • Female
  • Gestational Age
  • Glycoproteins / genetics*
  • Glycosylation
  • L-Selectin / metabolism*
  • Ligands
  • Mice
  • Mice, Inbred Strains
  • Molecular Sequence Data
  • Molecular Weight
  • Morphogenesis / physiology
  • Mucins / chemistry
  • Mucins / genetics*
  • Mucins / metabolism
  • Precipitin Tests
  • Protein Binding
  • Protein Structure, Secondary
  • Salivary Ducts / embryology
  • Submandibular Gland / embryology*

Substances

  • Glycoproteins
  • Ligands
  • Mucins
  • L-Selectin