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Abstract

Light- and dark-adaptation leads to changes in rhabdom morphology and photopigment distribution in the octopus retina. Molecular chaperones, including heat shock proteins (Hsps), may be involved in specific signaling pathways that cause changes in photoreceptor actin- and tubulin-based cytoskeletons and movement of the photopigments, rhodopsin and retinochrome. In this study, we used immunoblotting, in situ RT-PCR, immunofluorescence and confocal microscopy to localize the inducible form of Hsp70 and the larger Hsp90 in light- and dark-adapted and dorsal and ventral halves of adult octopus retinas. The Hsps showed differences in distribution between the light and dark and in dorsal vs. ventral position in the retina. Double labeling confocal microscopy co-localized Hsp70 with actin and tubulin, and Hsp90 with the photopigment, retinochrome. Our results demonstrate the presence of Hsp70 and Hsp90 in otherwise non-stressed light- and dark-adapted octopus retinas. These Hsps may help stabilize the cytoskeleton, important for rhabdom structure, and are perhaps involved in the redistribution of retinochrome in conditions of light and dark.

Heat Shock Proteins in the Human Eye

“…However, only HSC70 and Hsp86 were also found in the mature retina of rats. Others have also found Hsp70 in animal studies [47–49] just as Hsp40 [47] and Hsp90 [48] have been previously observed (Table 1). …”

Molecular characterization and induction of heat shock protein 90 in the Antarctic bivalve Laternula elliptica

“…They also play key roles in the maturation of signal transduction proteins, such as hormone receptors, protein kinases, and nitric oxide synthase, by forming specific complexes (Csermely et al 1998;Garcia-Cardena et al 1998;Imai and Yahara 2000;Richter and Buchner 2001). Although more than 100 genes belonging to the HSP90 family exist in various organisms (Chen et al 2006), little is known about HSP90 genes in mollusks (Tomanek and Somero 1999;Ochoa et al 2002;Farcy et al 2007;Gao et al 2007). To the best of our knowledge, full-length complementary DNA (cDNA) sequences of HSP90s have been cloned from only five mollusk species, Haliotis tuberculata, H. asinina, Chlamys farreri, Crassostrea gigas, and Argopecten irradians (Farcy et al 2007;Gao et al 2007Gao et al , 2008Gunter and Degnan 2007;Choi et al 2008).…”