Phosphofructokinase and pyruvate kinase of some crustacean and insect tissues

Molecular and kinetic properties of phosphofructokinase and pyruvate kinase of crustacean midgut gland, hypodermis, muscle and heart as well as of insect fat body and flight, body wall and heart muscles have been characterized and compared. The results suggest that the reaction catalyzed by the phosphofructokinase is the most important point for glycolysis regulation in all studied tissues. The phosphofructokinases exist in different interconvertible molecular forms and their activity is regulated by several positive and negative effectors. It is suggested that fructose-2,6-bisphosphate is the most powerful one and it plays a role of the signal which turns the glycolysis on. The pyruvate kinase is also a regulatory enzyme but only in those tissues for which gluconeogenesis is postulated, that is in the crustacean midgut gland and hypodermis as well as in the insect fat body. In these tissues, the enzyme is found in different molecular forms, which are characterized by higher or lower activity in different physiological stages of the tissue. A mechanism of interconversion between them has been explained and the existence of forms of lower activity has been connected with those stages for which gluconeogenesis operation is expected. In strictly glycolytic tissues like crustacean abdominal muscle or insect flight muscle, pyruvate kinase exists in a singular molecular form of high activity. The role of the phosphofructokinase and pyruvate kinase in the carbohydrate metabolism regulation of particular tissues is discussed

Phosphofructokinase and pyruvate kinase of some crustacean and insect tissues

Molecular and kinetic properties of phosphofructokinase and pyruvate kinase of crustacean midgut gland, hypodermis, muscle and heart as well as of insect fat body and flight, body wall and heart muscles have been characterized and compared. The results suggest that the reaction catalyzed by the phosphofructokinase is the most important point for glycolysis regulation in all studied tissues. The phosphofructokinases exist in different interconvertible molecular forms and their activity is regulated by several positive and negative effectors. It is suggested that fructose-2,6-bisphosphate is the most powerful one and it plays a role of the signal which turns the glycolysis on. The pyruvate kinase is also a regulatory enzyme but only in those tissues for which gluconeogenesis is postulated, that is in the crustacean midgut gland and hypodermis as well as in the insect fat body. In these tissues, the enzyme is found in different molecular forms, which are characterized by higher or lower activity in different physiological stages of the tissue. A mechanism of interconversion between them has been explained and the existence of forms of lower activity has been connected with those stages for which gluconeogenesis operation is expected. In strictly glycolytic tissues like crustacean abdominal muscle or insect flight muscle, pyruvate kinase exists in a singular molecular form of high activity. The role of the phosphofructokinase and pyruvate kinase in the carbohydrate metabolism regulation of particular tissues is discussed

TAXONOMY OF EUROPEAN LYMNAEIDAE (GASTROPODA: PULMONATA) IN STUDIES WITH THE USE OF MOLECULAR BIOLOGY TECHNIQUES. I. PRELIMINARY VIEW ON THE SUBGENUS STAGNICOLA LEACH, 1830 ON THE BASIS OF RAPD ANALYSIS

ABSTRACT: The random amplified polymorphic DNA (RAPD) technique was used to study genomic relationships of five lymnaeid species: (Linnaeus, 1758). Altogether 253 characters (253 DNA fragments obtained in PCR) were scored and characters were used to create a matrix of pairwise distances between all the pairs of taxa. Distance data UPGMA cluster and Camin-Sokal maximum parsimony analyses were applied for dendrogram construction. The results support the discrimination of all taxa as separate species which was suggested by the structure of their reproductive organs. The taxonomic status of L. occulta (Jack.) as a member of the subgenus Stagnicola Leach, 1830 is discussed

The complete mitochondrial genome of the terrestrial snail Monacha cartusiana (O.F. Müller, 1774) (Gastropoda, Eupulmonata, Hygromiidae)

The mitochondrial genome of Monacha cartusiana is the first complete mitochondrial sequence described for the pulmonate snail genus Monacha and for the family Hygromiidae. The identified mitogenome has a length of 13,894 bp and encodes 13 proteins, 22 tRNAs, and two rRNAs. A phylogenetic analysis of available mitogenomes from representatives of helicoid families shows a sister group relationship of Hygromiidae and Geomitridae, which have been recently recognised as separate families

Exploration of phylogeography of Monacha cantiana s.l. continues: the populations of the Apuan Alps (NW Tuscany, Italy) (Eupulmonata, Stylommatophora, Hygromiidae)

Two new lineages CAN-5 and CAN-6 were recognised in four populations of Monacha cantiana (Montagu, 1803) s.l. from the Italian Apuan Alps by joint molecular and morphological analysis. They are different from other M. cantiana lineages known from English, Italian, Austrian and French populations, i.e. CAN-1, CAN-2, CAN-3 and CAN-4, as well as from the other Italian Monacha species used for comparisons (M. parumcincta and M. cartusiana). Although a definite taxonomic and nomenclatural setting seems to be premature, we suggest that the name or names for these new lineages as one or two species should be found among 19th century names (Helix sobara Mabille, 1881, H. ardesa Mabille, 1881, H. apuanica Mabille, 1881, H. carfaniensis De Stefani, 1883 and H. spallanzanii De Stefani, 1884)

Nicotine affects protein complex rearrangement in <i>Caenorhabditis elegans</i> cells

<p>Nicotine may affect cell function by rearranging protein complexes. We aimed to determine nicotine-induced alterations of protein complexes in <i>Caenorhabditis elegans</i> (<i>C. elegans</i>) cells, thereby revealing links between nicotine exposure and protein complex modulation. We compared the proteomic alterations induced by low and high nicotine concentrations (0.01 mM and 1 mM) with the control (no nicotine) <i>in vivo</i> by using mass spectrometry (MS)-based techniques, specifically the cetyltrimethylammonium bromide (CTAB) discontinuous gel electrophoresis coupled with liquid chromatography (LC)–MS/MS and spectral counting. As a result, we identified dozens of <i>C. elegans</i> proteins that are present exclusively or in higher abundance in either nicotine-treated or untreated worms. Based on these results, we report a possible network that captures the key protein components of nicotine-induced protein complexes and speculate how the different protein modules relate to their distinct physiological roles. Using functional annotation of detected proteins, we hypothesize that the identified complexes can modulate the energy metabolism and level of oxidative stress. These proteins can also be involved in modulation of gene expression and may be crucial in Alzheimer’s disease. The findings reported in our study reveal putative intracellular interactions of many proteins with the cytoskeleton and may contribute to the understanding of the mechanisms of nicotinic acetylcholine receptor (nAChR) signaling and trafficking in cells.</p