ABSTRACT: The biomarker concept involves the use of biochemical, cellular and physiological parameters as screening tools in environmental surveillance. Stress proteins, such as heat shock proteins (HSPs), fulfill many of the requirements for being ideal candidates in a biomarker strategy for environmental monitoring. Sponges (Porifera) are one of the major phyla found in the marine hard-substrate benthos, both with respect to the number of species and biomass. However, only recently have genes from sponges been cloned. Here we describe the isolation of the cDNA encoding a heat shock protein of M_r (relative molecular weight) 70 kDa (HSP70). The cDNA HSP70 from the marine sponge Geodia cydonium has a length of 2.3 kb and encodes an AA sequence of M_r 72579. The sponge HSP70 displays characteristic features of the HSP70 family. The HSP70 protein is induced by natural stressors including changes in temperature as well as pH, as demonstrated by Western blot analysis. No response was observed after treating the samples with hypotonic or hypertonic conditions. Our results provide the first molecular evidence that HSP70 of sponges is a useful biomarker.

KEY WORDS: Geodia cydonium . Sponges . Heat shock protein . HSP70 . Environmental stress . Biomarker

Published in MEPS Vol. 136 (1996) on June 6
ISSN: 0171-8630. Copyright © Inter-Research, Oldendorf/Luhe, 1996