Universität zu Köln

Doelling, Ramona, Becker, Doerthe, Hawat, Susan, Koch, Marita, Schwarzenberger, Anke and Zeis, Bettina (2016). Adjustments of serine proteases of Daphnia pulex in response to temperature changes. Comp. Biochem. Physiol. B-Biochem. Mol. Biol., 194. S. 1 - 11. NEW YORK: ELSEVIER SCIENCE INC. ISSN 1879-1107

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Abstract

Elevated temperatures considerably challenge aquatic invertebrates, and enhanced energy metabolism and protein turnover require adjustments of digestion. In Daphnia, the serine proteases chymotrypsin and trypsin represent the major proteolytic enzymes. Daphnia pulex acclimated to different temperature conditions or subjected to acute heat stress showed increased expression level of serine proteases with rising temperatures. Transcripts of trypsin isoforms were always present in higher amounts than observed for chymotrypsin. Additionally, trypsin isoform transcripts were induced by elevated temperatures to a larger extent. Correspondingly, trypsin activity dominated in cold-acclimated animals. However, the enzymatic activity of chymotrypsin increased at elevated temperatures, whereas trypsin activity slightly decreased, resulting in a shift to dominating chymotrypsin activity in warm-acclimated animals. Zymograms revealed eight bands with proteolytic activity in the range of 20 to 86 kDa. The single bands were assigned to trypsin or chymotrypsin activity applying specific inhibitors or from casein cleavage products identified by mass spectrometric analysis. The total amount of proteolytic activity was elevated with acclimation temperature increase and showed a transient decrease under acute heat stress. The contribution of the different isoforms to protein digestion indicated induction of chymotrypsin with increasing acclimation temperature. For trypsin, the share of one isoform decreased with elevated temperature, while another isoform was enhanced. Thus differential expression of serine proteases was observed in response to chronic and acute temperature changes. The observed phenotypic plasticity adjusts the set of active proteases to the altered needs of protein metabolism optimizing protein digestion for the temperature conditions experienced in the habitat. (C) 2016 Elsevier Inc. All rights reserved.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Doelling, Ramona UNSPECIFIED UNSPECIFIED UNSPECIFIED Becker, Doerthe UNSPECIFIED UNSPECIFIED UNSPECIFIED Hawat, Susan UNSPECIFIED UNSPECIFIED UNSPECIFIED Koch, Marita UNSPECIFIED UNSPECIFIED UNSPECIFIED Schwarzenberger, Anke UNSPECIFIED UNSPECIFIED UNSPECIFIED Zeis, Bettina UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-280208
DOI:	10.1016/j.cbpb.2016.01.001
Journal or Publication Title:	Comp. Biochem. Physiol. B-Biochem. Mol. Biol.
Volume:	194
Page Range:	S. 1 - 11
Date:	2016
Publisher:	ELSEVIER SCIENCE INC
Place of Publication:	NEW YORK
ISSN:	1879-1107
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language GENE-EXPRESSION; MASS-SPECTROMETRY; MAGNA; ACCLIMATION; ADAPTATION; STRESS; GENOME; SIZE Multiple languages Biochemistry & Molecular Biology; Zoology Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/28020