Wall-associated kinases are expressed throughout plant development and are required for cell expansion.
The mechanism by which events in the angiosperm cell wall are communicated to the cytoplasm is not well characterized. A family of five Arabidopsis wall-associated kinases (WAKs) have the potential to provide a physical and signaling continuum between the cell wall and the cytoplasm. The WAKs have an active cytoplasmic protein kinase domain, span the plasma membrane, and contain an N terminus that binds the cell wall. We show here that WAKs are expressed at organ junctions, in shoot and root apical meristems, in expanding leaves, and in response to wall disturbances. Leaves expressing an antisense WAK gene have reduced WAK protein levels and exhibit a loss of cell expansion. WAKs are covalently bound to pectin in the cell wall, providing evidence that the binding of a structural carbohydrate by a receptor-like kinase may have significance in the control of cell expansion.
Biology Department, Room B353, LSRC, Duke University, Durham, North Carolina 27708, USA.
T A
TA
Wagner
B D
BD
Kohorn
D017360:Arabidopsis / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins; D001483:Base Sequence; D002473:Cell Wall / Q000201:enzymology; D018744:DNA, Plant / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020319:Oligodeoxyribonucleotides, Antisense / Q000235:genetics; D010368:Pectins / Q000378:metabolism; D018515:Plant Leaves / Q000166:cytology / Q000201:enzymology; D030821:Plants, Genetically Modified; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
D029681:Arabidopsis Proteins; D018744:DNA, Plant; D007527:Isoenzymes; D008565:Membrane Proteins; D020319:Oligodeoxyribonucleotides, Antisense; D010368:Pectins; D011494:Protein Kinases; C101093:WAK1 protein, Arabidopsis