Purification and cloning of an arabinogalactan-protein from xylem of loblolly pine

Planta. 2000 Mar;210(4):686-9. doi: 10.1007/s004250050061.


An arabinogalactan-protein (AGP) was purified from differentiating xylem of loblolly pine (Pinus taeda L.) and the N-terminal sequence used to identify a cDNA clone. The protein, PtaAGP3, was not coded for by any previously identified AGP-like genes. Moreover, PtaAGP3 was abundantly and preferentially expressed in differentiating xylem. The encoded protein contains four domains, a signal peptide, a cleaved hydrophilic region, a region rich in serine, alanine, and proline/hydroxyproline, and a hydrophobic C-terminus. It is postulated to contain a GPI (glycosylphosphatidylinositol) anchor site. If the protein is cleaved at the putative GPI anchor site, as has been observed in other classical AGPs, all but the Ser-Ala-Pro/Hyp-rich domain may be missing from the mature protein. Xylem-specific AGPs are hypothesized to be involved in xylem development.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Blotting, Northern
  • Cloning, Molecular
  • Electrophoresis, Polyacrylamide Gel
  • Molecular Sequence Data
  • Mucoproteins / chemistry
  • Mucoproteins / isolation & purification*
  • Mucoproteins / metabolism
  • Pinus taeda
  • Plant Proteins / chemistry
  • Plant Proteins / isolation & purification*
  • Plant Proteins / metabolism
  • RNA, Plant / analysis


  • Mucoproteins
  • Plant Proteins
  • RNA, Plant
  • arabinogalactan proteins