Purification and cloning of an arabinogalactan-protein from xylem of loblolly pine.
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.
Loopstra
C A
CA
Department of Forest Science and Crop Biotechnology Center, Texas A&M University, College Station 77843, USA.
Puryear
J D
JD
No
E G
EG
D000595:Amino Acid Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D009088:Mucoproteins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D041603:Pinus taeda; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D018749:RNA, Plant / Q000032:analysis
D009088:Mucoproteins; D010940:Plant Proteins; D018749:RNA, Plant; C006619:arabinogalactan proteins