Identification of a novel peptide motif that mediates cross-linking of proteins to cell walls.
A cDNA clone representing a member of a novel class of cell wall proteins was isolated from tobacco plants. We have designated this protein NtTLRP for tyrosine- and lysine-rich protein. It is structurally related to the previously identified TLRP from tomato plants, sharing a high amino-acid sequence similarity at the C-terminal region. This region contains what appears to be a novel peptide motif which we call CD for cysteine-rich domain, and which is common to several other cell-wall proteins. By using a functional test in transgenic plants, we demonstrate that the presence of the CD domain is per se sufficient to cross-link previously soluble proteins to the cell wall. We present evidence that NtTLRP is cross-linked and specifically localizes to the cell wall of lignified cells. The highly localized deposition of NtTLRP in these cells indicates that this class of cell-wall proteins may have a specialized function in the formation of xylem tissue.
Domingo
C
C
Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica-Consejo Superior de Investigaciones Científicas, Camino de Vera s/n, 46022-Valencia, Spain.
Saurí
A
A
Mansilla
E
E
Conejero
V
V
Vera
P
P
D000595:Amino Acid Sequence; D002473:Cell Wall / Q000502:physiology; D002478:Cells, Cultured; D003432:Cross-Linking Reagents; D018076:DNA, Complementary; D016326:Extracellular Matrix Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000502:physiology; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D010947:Plants, Toxic; D021382:Protein Sorting Signals / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic
D003432:Cross-Linking Reagents; D018076:DNA, Complementary; D016326:Extracellular Matrix Proteins; D010940:Plant Proteins; D021382:Protein Sorting Signals; C490344:TLRP protein, Nicotiana tabacum