Molecular cloning of a novel phytochrome gene of the moss Ceratodon purpureus which encodes a putative light-regulated protein kinase.
The phytochrome gene (phyCer) of the moss Ceratodon purpureus was isolated and characterized. phyCer is composed of three coding exons: exon I of 2035 bp, exon II of 300 bp and exon III of 1574 bp. The deduced polypeptide encoded by exon I and II exhibits substantial sequence homology to the conserved NH2-terminal chromophore domain of known phytochromes. In contrast, the COOH-terminal polypeptide encoded by exon III shows no sequence homology to any phytochrome molecule. phyCer most likely represents a single-copy gene and is expressed in a light-independent manner. From the DNA sequence analysis it can be deduced that the PhyCer polypeptide is composed of 1303 amino acids (including the starting Met) which predicts a molecular mass for PhyCer of 145 kDa. The polypeptide encoded in exon III exhibits striking homology within the 300 carboxy-terminal amino acids to the catalytic domain of protein kinases. The carboxy terminus of PhyCer was found to be most homologous to protein-tyrosine kinases of Dictyostelium discoideum and to the products of retroviral oncogenes which belong to the Raf-Mos serine/threonine kinase family. From the hydropathy profile PhyCer appears to be a soluble protein. The predicted structure suggests that PhyCer represents a soluble light-sensor protein kinase which is linked with a cellular phosphorylating cascade.
Thümmler
F
F
Botanisches Institut, Universität München, Germany.
Dufner
M
M
Kreisl
P
P
Dittrich
P
P
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D016384:Consensus Sequence; D015870:Gene Expression; D017343:Genes, Plant; D008027:Light; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D010802:Phylogeny; D010834:Phytochrome / Q000235:genetics*; D010944:Plants / Q000235:genetics*; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D015183:Restriction Mapping; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D010834:Phytochrome; D011494:Protein Kinases