David A. Prentice

CHITINASE IN INSECTIVOROUS BATS

Abstract Chitinase was found in the intestines of 9 species of 6 genera of bats of Indiana. Included were the northern myotis, Myotis septentrionalis; the little brown myotis, M. lucifugus; the Indiana myotis, Myotis sodalis, the big brown bat, Eptesicus fuscus, the eastern pipistrelle, Pipistrellus subflavus, the evening bat, Nycticeius humeralis, the red bat, Lasiurus borealis, the hoary bat, L. cinereus, and the silver-haired bat, Lasionycteris noctivagans. Chitinase was found in summer and in winter, but at significantly lower levels in winter. Chitinase in summer may help to separate parts of insects by breaking down softer connective tissue. In winter, it may break down remnants of chitin left over from summer foraging and could even serve as a supplemental source of energy and nutrients. Chitinase was produced in these bats by 6 previously known species of chitinase-producing bacteria, 2 of Serratia, 3 of Bacillus, and 1 of Enterobacter, and by 4 species previously unknown to produce chitinase, Hafnia alvei, Citrobacter amelonaticus, Enterobacter aerogenes, and E. cloacae.

Increases in p11 and annexin II proteins correlate with differentiation in the PC12 pheochromocytoma

Regulation of p11 and annexin II by nerve growth factor, staurosporine, and epidermal growth factor was examined in PC12 rat adrenal pheochromocytoma cells using immunoblot analysis. Nerve growth factor, which is known to induce neurite outgrowth in PC12 cells, stimulated a five-fold increase in p11 and the higher levels of p11 were characteristic of PC12 cells exposed to nerve growth factor for up to ten days. Nerve growth factor induced an even greater increase (13.6-fold) in annexin II. Staurosporine, a protein kinase inhibitor that at high concentrations induces neurite formation, was as effective as nerve growth factor in increasing the intracellular levels of p11 and annexin II. Epidermal growth factor was less effective than nerve growth factor and staurosporine, producing only a two-fold increase in p11 and a three-fold increase in annexin II. The ineffectiveness of epidermal growth factor in increasing intracellular levels of p11 and annexin II is consistent with the fact that epidermal growth factor does not stimulate neurite outgrowth in PC12 cells. Evidence presented here suggests that p11 and/or annexin II may play a role in PC12 cell differentiation.

Identification of stathmin-like proteins in plants

Abstract Stathmin-like proteins were identified in broad bean, green bean, pea, soybean, and cowpea extracts by western blotting after SDS PAGE and native isoelectric focusing (IEF). The subunit molecular mass of these proteins ranged from 14–23 kDa in leaf, root and stem tissues, but higher molecular mass forms were observed in germinated seed (cotyledon) extracts. After IEF, multiple forms of stathmin-like proteins were observed in different tissues from all plant extracts. In general, the pIs ranged from 3.5 to 5.0, although each tissue showed a unique IEF pattern of stathmin-like proteins. Stathmin-like proteins in plants appear to be similar to mammalian stathmin in size, pI, and immunological determinants.