A Study on the Origin of Peroxisomes: Possibility of Actinobacteria Symbiosis

The origin of peroxisomes as having developed from the endoplasmic reticulum (ER) was proposed on the basis of the similarity between some peroxisomal proteins and ER proteins, and the localization of some peroxisomal proteins on the ER. To study the evolutionary distance between peroxisomes and ER and Prokaryotes, we carried out a phylogenetic analysis of CDC48 (cell division control 48) and its homologs, including ER-localized CDC48, CDC48 homologs in Prokaryotes and peroxisome-localized PEX1 and PEX6. A similarity search analysis of peroxisomal protein sequences to prokaryotic protein sequences using BLAST at several thresholds (E-values) was also done. We propose Actinobacteria symbiosis for the origin of peroxisomes based on the following evidence: (1) PEX1 and PEX6 are close in distance to CDC48 homologs in Actinobacteria, and these distances are closer than to ER-localized CDC48. (2) Actinobacteria proteins show the highest degree of similarity to peroxisomal proteins compared with other prokaryotes

Polyamines of Planarians and Leeches : The Presence of Homospermidine

Polyamines of the planarian, Dugesia tigrina and the leech, Haemadipsa zeylanica were analyzed by high-performance liquid chromatography. An uncommon polyamine, homospermidine, in addition to putrescine, cadaverine, spermidine, spermine and agmatine, was detected in the two organisms. Spermidine and spermine levels increased during regeneration in D. tigrina

Activation of cGMP phosphodiesterase by purified green rod pigment from frog retina

AbstractActivation of cGMP phosphodiesterase(PDE) of frog rod outer segments (ROS) by purified green rod pigment (GRP) was analyzed. GRP activated PDE in a similar manner to purified rhodopsin. This activation required illumination of the pigment and presence of GTP

Gamma Irradiation Effects on Cultured Cells: Investigated by the MTT Method

Effects of gamma-irradiation, given in the range of 5 to 30 Gy on Caski cells (Epitheloid carcinoma from the cervix) were investigated by the MIT (3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyl tetrazolium bromide) method. Results were compared with data assessed simultaneously from cell number counts. The sizes of cells irradiated with 10 to 30 Gy were larger than those of unirradiated ones, and each irradiated cell reduced a larger amount of MT[ than did each unirradiated cell. Irradiation in the above range, therefore causes Caski cells to lose their ability to divide, but the effect on the mitochondria was very slight. Application of the MIT method to the irradiated cells should be done with care. Because, in the irradiated cells depending on the irradiation dose, the MTT activity does not correlate to the cell number

HPLC Analysis of Retinoids Extracted from the Planarian, Dugesia japonica(Physology)

Volume: 9Start Page: 941End Page: 94