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Melatonin biosynthesis in the thymus of humans and rats 总被引:2,自引:0,他引:2
Naranjo MC Guerrero JM Rubio A Lardone PJ Carrillo-Vico A Carrascosa-Salmoral MP Jiménez-Jorge S Arellano MV Leal-Noval SR Leal M Lissen E Molinero P 《Cellular and molecular life sciences : CMLS》2007,64(6):781-790
Melatonin is an indoleamine widely distributed in the evolution that shows a great functional versatility, playing an important
role as a transmitter of photoperiodic information and exhibiting antioxidant, oncostatic, anti-aging and immunomodulatory
properties. In vertebrates, this molecule is produced by the pineal gland and other extrapineal sites. The present study was
carried out to investigate the presence of melatonin in thymus and the possibility of an endogenous melatonin synthesis in
this organ, in which T cells are matured. In this work, we demonstrate in humans and rats that thymus contains melatonin,
expresses the mRNAs encoding N-acetyltransferase and hydroxyindol-O-methyltransferase, the two key enzymes of the melatonin synthesis, and has this biosynthetic machinery activated. In addition,
rat thymocytes cultured for 24 h exhibited high levels of melatonin. The results presented here suggest that human and rat
thymuses are able to synthesize melatonin, which could have intracrine, autocrine and paracrine functions.
Received 30 September 2006; received after revision 30 December 2006; accepted 15 February 2007 相似文献
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Genome divergence in two Prochlorococcus ecotypes reflects oceanic niche differentiation 总被引:1,自引:0,他引:1
Rocap G Larimer FW Lamerdin J Malfatti S Chain P Ahlgren NA Arellano A Coleman M Hauser L Hess WR Johnson ZI Land M Lindell D Post AF Regala W Shah M Shaw SL Steglich C Sullivan MB Ting CS Tolonen A Webb EA Zinser ER Chisholm SW 《Nature》2003,424(6952):1042-1047
The marine unicellular cyanobacterium Prochlorococcus is the smallest-known oxygen-evolving autotroph. It numerically dominates the phytoplankton in the tropical and subtropical oceans, and is responsible for a significant fraction of global photosynthesis. Here we compare the genomes of two Prochlorococcus strains that span the largest evolutionary distance within the Prochlorococcus lineage and that have different minimum, maximum and optimal light intensities for growth. The high-light-adapted ecotype has the smallest genome (1,657,990 base pairs, 1,716 genes) of any known oxygenic phototroph, whereas the genome of its low-light-adapted counterpart is significantly larger, at 2,410,873 base pairs (2,275 genes). The comparative architectures of these two strains reveal dynamic genomes that are constantly changing in response to myriad selection pressures. Although the two strains have 1,350 genes in common, a significant number are not shared, and these have been differentially retained from the common ancestor, or acquired through duplication or lateral transfer. Some of these genes have obvious roles in determining the relative fitness of the ecotypes in response to key environmental variables, and hence in regulating their distribution and abundance in the oceans. 相似文献
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