Cloning and deduced amino acid sequence of a novel cartilage protein (CILP) identifies a proform including a nucleotide pyrophosphohydrolase

J Biol Chem. 1998 Sep 4;273(36):23469-75. doi: 10.1074/jbc.273.36.23469.

Abstract

The cDNA cloning and expression in vitro and in eukaryotic cells of a novel protein isolated from human articular cartilage, cartilage intermediate layer protein (CILP) is described. A single 4. 2-kilobase mRNA detected in human articular cartilage encodes a polypeptide of 1184 amino acids with a calculated molecular mass of 132.5 kDa. The protein has a putative signal peptide of 21 amino acids, and is a proform of two polypeptides. The amino-terminal half corresponds to CILP (molecular mass of 78.5 kDa, not including post-translational modifications) and the carboxyl-terminal half corresponds to a protein homologous to a porcine nucleotide pyrophosphohydrolase, NTPPHase (molecular mass of 51.8 kDa, not including post-translational modifications). CILP has 30 cysteines and six putative N-glycosylation sites. The human homolog of porcine NTPPHase described here contains 10 cysteine residues and two putative N-glycosylation sites. In the precursor protein the NTPPHase region is immediately preceded by a tetrapeptide conforming to a furin proteinase cleavage consensus sequence. Expression of the full-length cDNA in a cell-free translation system and in COS-7 or EBNA cells indicates that the precursor protein is synthesized as a single polypeptide chain that is processed, possibly by a furin-like protease, into two polypeptides upon or preceding secretion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • COS Cells
  • Cartilage / chemistry*
  • Chondrocytes / metabolism
  • Cloning, Molecular
  • DNA, Complementary / genetics
  • Extracellular Matrix Proteins / chemistry
  • Extracellular Matrix Proteins / genetics*
  • Extracellular Matrix Proteins / metabolism
  • Glycoproteins / chemistry
  • Glycoproteins / genetics*
  • Glycoproteins / metabolism
  • Humans
  • Molecular Sequence Data
  • Peptide Mapping
  • Polymerase Chain Reaction
  • Protein Precursors / genetics*
  • Protein Processing, Post-Translational
  • Pyrophosphatases / genetics*
  • Recombinant Proteins / biosynthesis
  • Restriction Mapping
  • Sequence Analysis
  • Sequence Homology, Amino Acid

Substances

  • DNA, Complementary
  • Extracellular Matrix Proteins
  • Glycoproteins
  • Protein Precursors
  • Recombinant Proteins
  • CILP protein, human
  • Pyrophosphatases
  • nucleotide pyrophosphatase

Associated data

  • GENBANK/AF035408