Molecular characterization of type 1 serine/threonine phosphatases from Brassica oleracea.
We describe the isolation of cDNA clones encoding type 1 serine/threonine protein phosphatase (PP1) from Brassica oleracea stigmas. We demonstrate that PP1 form a multigene family in Brassica. Within their most conserved domain, these phosphatases are 80-90% identical at the amino acid level. One cDNA (BoPP1) was found to encode a protein that shows 78-80% sequence identity to maize, rabbit, and yeast PP1. The accumulation of BoPP1 mRNA is developmentally regulated. Varying levels of BoPP1-homologous transcripts were detected in leaves, cotyledons, pistils, anthers and roots. In addition, distinct species of BoPP1 transcripts accumulated at different stages of Brassica microspore development, and mature trinucleate microspores contained a unique BoPP1 mRNA species not found at other stages of the plant's life cycle. Lastly, we show by genomic Southern blots that the Brassica genome might contain homologues of the mammalian PP1 inhibitor-1.
Rundle
S J
SJ
Section of Plant Biology, Cornell University, Ithaca, NY 14853.
Nasrallah
J B
JB
D000595:Amino Acid Sequence; D001483:Base Sequence; D001937:Brassica / Q000201:enzymology / Q000235:genetics*; D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D015723:Gene Library; D017343:Genes, Plant / Q000235:genetics*; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D010749:Phosphoprotein Phosphatases / Q000235:genetics*; D011058:Pollen / Q000502:physiology; D011506:Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000235:genetics; D014018:Tissue Distribution
D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D011506:Proteins; D012333:RNA, Messenger; C021042:protein phosphatase inhibitor-1; D010749:Phosphoprotein Phosphatases