An Arabidopsis thaliana protein homologous to cyanobacterial high-light-inducible proteins.
An Arabidopsis thaliana cDNA clone encoding a novel 110 amino acid thylakoid protein has been sequenced. The in vitro synthesized protein is taken up by intact chloroplasts, inserted into the thylakoid membrane and the transit peptide is cleaved off during this process. The mature protein is predicted to contain 69 amino acids, to form one membrane-spanning alpha-helix and to have its N-terminus at the stromal side of the thylakoid membrane. The protein showed similarity to the LHC, ELIP and PsbS proteins of higher plants, but more pronounced to the high-light-inducible proteins (HLIPs) of cyanobacteria and red algae, to which no homologue previously has been detected in higher plants. As for HLIP and ELIP, high light increases the mRNA levels of the corresponding gene. Sequence comparisons indicate that the protein may bind chlorophyll and form dimers in the thylakoid membrane. The level of expression of the protein seems to be far lower than that of normal PSI and PSII subunits.
Jansson
S
S
Umeå Plant Science Center, Department of Plant Physiology, Umeå University, Sweden.
Andersson
J
J
Kim
S J
SJ
Jackowski
G
G
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000528:radiation effects; D001426:Bacterial Proteins; D001483:Base Sequence; D002736:Chloroplasts / Q000378:metabolism; D002940:Circadian Rhythm; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D008027:Light; D045342:Light-Harvesting Protein Complexes; D008969:Molecular Sequence Data; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics* / Q000493:pharmacokinetics; D011498:Protein Precursors / Q000493:pharmacokinetics; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D018076:DNA, Complementary; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D010940:Plant Proteins; D011498:Protein Precursors; D018749:RNA, Plant; C091582:high light-inducible protein, cyanobacteria