ABSTRACT
CDC-48 is a AAA (ATPases associated with diverse cellular activities) chaperone and participates in a wide range of cellular activities. Its functional diversity is determined by differential binding of a variety of cofactors. In this study, we analyzed the physiological role of a CDC-48 cofactor UBXN-6 in Caenorhabditis elegans. The amount of UBXN-6 was markedly increased upon starvation, but not with the treatment of tunicamycin and rapamycin. The induction upon starvation is a unique characteristic for UBXN-6 among C-terminal cofactors of CDC-48. During starvation, lysosomal activity is triggered for rapid clearance of cellular materials. We observed the lysosomal activity by monitoring GLO-1::GFP, a marker for lysosome-related organelles. We found that more puncta of GLO-1::GFP were observed in the ubxn-6 deletion mutant after 12â¯h starvation compared with the wild-type strain. Taken together, we propose that UBXN-6 is involved in clearance of cellular materials upon starvation in C. elegans.
Subject(s)
Caenorhabditis elegans Proteins/metabolism , Caenorhabditis elegans/physiology , Intracellular Signaling Peptides and Proteins/metabolism , N-Ethylmaleimide-Sensitive Proteins/metabolism , Valosin Containing Protein/metabolism , Animal Nutritional Physiological Phenomena , Animals , CRISPR-Cas Systems , Caenorhabditis elegans/genetics , Caenorhabditis elegans Proteins/genetics , Eating , Gene Deletion , Hunger , Intracellular Signaling Peptides and Proteins/genetics , Lysosomes/genetics , Lysosomes/metabolism , Male , Protein Interaction MapsABSTRACT
The cellulolytic bacteria from the gut of three different phytophagous insects were studied to isolate novel cellulolytic organism for biofuel industry. Among the threse, gut of P. quatuordecimpunctata larvae contained both highest no of total bacterial count (6.8x107 CFU/gut) and cellulolytic bacteria (5.42x103 CFU/gut). Fifteen different isolates were obtained from the gut of O. velox, A. miliaris and P. quatuordecimpunctata. All the isolates produced clear zone in CMC medium staining with Congo red. The isolates included Gram positive Enterococcus, Microbacterium and Gram negative Aeromonas, Erwinia, Serretia, Flavobacterium, Acenitobacter, Klebsiella, Yersinia, Xenorhabdus, Psedomonas and Photorhabdus. Out of the fifteen isolated and identified bacterial species, twelve bacterial species were novel being reported for first time as having cellulase activity.
ABSTRACT
Endo-beta-1, 4-glucanase (EC 3.2.1.4) activity was measured in the gut fluid of phytophagous insect Podontia quatuordecimpunctata Linnaeus (Coleoptera: Chrysomelidae) in different days of development. The eight day-old larva showed maximum activity with 1.73 U mg(-1) of protein, which was confirmed by gel zymography. In zymogram, using Carboxymethyl Cellulose (CMC) as substrate, four distinct cellulolytic protein bands were detected in leaf borer gut fluids through out of its development. The optimum temperature and pH were 60 degrees C and 5.0, respectively. This endo-beta-1,4-glucanase showed maximum stability at 20-45 degrees C with approximately 20% remaining activity. Zymography also showed complete loss of endo-beta-1,4 glucanase activity at 55 degrees C. This is the first report that the cellulolytic enzyme is produced in the gut of P. quatuordecimpunctata through the whole developmental stages, from the 1st instar to the adult, except for pupae.
