Calcium regulation in crustaceans during the molt cycle: a review and update

The porcelain crab Petrolisthes cinctipes lives under rocks and in mussel beds in the mid-intertidal zone where it experiences immersion during high tide and saturating humid conditions in air during low tide, which can increase habitat temperature by up to 20°C. To identify the biochemical changes affected by increasing temperature fluctuations and subsequent heat shock, we acclimated P. cinctipes for 30 days to one of three temperature regimes: (1) constant 10°C, (2) daily temperature fluctuations between 10 and 20°C (5 h up-ramp to 20°C, 1 h down-ramp to 10°C) and (3) 10-30°C (up-ramp to 30°C). After acclimation, animals were exposed to either 10°C or a 30°C heat shock to analyze the proteomic changes in claw muscle tissue. Following acclimation to 10-30°C (measured at 10°C), enolase and ATP synthase increased in abundance. Following heat shock, isoforms of arginine kinase and glycolytic enzymes such as aldolase, triose phosphate isomerase and glyceraldehyde 3-phosphate dehydrogenase increased across all acclimation regimes. Full-length isoforms of hemocyanin increased abundance following acclimation to 10-30°C, but hemocyanin fragments increased after heat shock following constant 10°C and fluctuating 10-20°C, possibly playing a role as antimicrobial peptides. Following constant 10°C and fluctuating 10-20°C, paramyosin and myosin heavy chain type-B increased in abundance, respectively, whereas myosin light and heavy chain decreased with heat shock. Actin-binding proteins, which stabilize actin filaments (filamin and tropomyosin), increased during heat shock following 10-30°C; however, actin severing and depolymerization proteins (gelsolin and cofilin) increased during heat shock following 10-20°C, possibly promoting muscle fiber restructuring. RAF kinase inhibitor protein and prostaglandin reductase increased during heat shock following constant 10°C and fluctuating 10-20°C, possibly inhibiting an immune response during heat shock. The results suggest that ATP supply, muscle fiber restructuring and immune responses are all affected by temperature fluctuations and subsequent acute heat shock in muscle tissue. Furthermore, although heat shock after acclimation to constant 10°C and fluctuating 10-30°C showed the greatest effects on the proteome, moderately fluctuating temperatures (10-20°C) broadened the temperature range over which claw muscle was able to respond to an acute heat shock with limited changes in the muscle proteome. INTRODUCTIONEnvironmental temperature has a ubiquitous effect on rates of biochemical reactions and cellular structures in ectothermic organisms, which have adapted their cellular processes and structures to cope with the specific thermal properties of their habitat (Somero, 2012;Tomanek, 2010). An organism's ability to adjust biochemical processes to different body temperatures is in large part determined by the rate and amplitude of temperature change and its evolutionary history, e.g. the thermal environment it occupies and recent thermal history, e.g. acclimatization. For...

Section: Signaling Proteins Calcium Ion Regulationmentioning

confidence: 99%

The proteomic response of cheliped myofibril tissue in the eurythermal porcelain crabPetrolisthes cinctipesto heat shock following acclimation to daily temperature fluctuations

Garland

Stillman

Tomanek

2015

“…It is further distinct from these exchangers in that it exhibits strong calcium-dependence (Ahearn and Franco, 1990;Zhuang and Ahearn, 1996). This exchanger is capable of transporting calcium across the apical surface and thus performs a potentially important role in calcium homeostasis (Ahearn et al, 2004). It appears that calcium and sodium share the same transport site, as these ions reciprocally inhibit the others passage in a competitive manner (Ahearn and Franco, 1990).…”

Section: Effect Of Ph On Sodium Influx In Daphnia Magna Is Calcium Dementioning

confidence: 99%

Physiological characterisation of a pH- and calcium-dependent sodium uptake mechanism in the freshwater crustacean,Daphnia magna

Glover

Wood

2005

SUMMARY Daphnia are highly sensitive to sodium metabolism disruption caused by aquatic acidification and ionoregulatory toxicants, due to their finely balanced ion homeostasis. Nine different water chemistries of varying pH (4, 6 and 8) and calcium concentration (0, 0.5 and 1 mmol l–1) were used to delineate the mechanism of sodium influx in Daphnia magna. Lowering water pH severely inhibited sodium influx when calcium concentration was high, but transport kinetic analysis revealed a stimulated sodium influx capacity (Jmax) when calcium was absent. At low pH increasing water calcium levels decreased Jmax and raised Km (decreased sodium influx affinity), while at high pH the opposite pattern was observed (elevated Jmax and reduced Km). These effects on sodium influx were mirrored by changes in whole body sodium levels. Further examination of the effect of calcium on sodium influx showed a severe inhibition of sodium uptake by 100 μmol l–1 calcium gluconate at both low (50 μmol l–1) and high (1000 μmol l–1) sodium concentrations. At high sodium concentrations,stimulated sodium influx was noted with elevated calcium levels. These results, in addition to data showing amiloride inhibition of sodium influx(Ki=180 μmol l–1), suggest a mechanism of sodium influx in Daphnia magna that involves the electrogenic 2Na+/1H+ exchanger.

“…Maximal Ca 2+ -ATPase activity assays yielded values that were higher than reported values in the literature from rainbow trout and crucian carp heart, and also from plantaris in rats (Fig.5B) (Aho and Vornanen, 1998;Inashima et al, 2003). However, maximal activity of Ca 2+ -ATPase in crustacean muscle has been reported to be up to two orders of magnitude greater than that of comparable vertebrate Ca 2+ -ATPases in muscle (Ahearn et al, 2004;Van der Kloot, 1969;Baskin, 1971) and the TEM images used for mitochondrial volume density in this study revealed large amounts of SR throughout the tissue compared with fish tissue (data not shown). Deamer (Deamer, -ATPase is very similar to that in mammals, although the specific activity of the enzyme was among the highest reported.…”

Section: Discussionmentioning

confidence: 74%

An evaluation of muscle maintenance costs during fiber hypertrophy in the lobster Homarus americanus: are larger muscle fibers cheaper to maintain?

Jiménez

Dasika

Locke

et al. 2011

SUMMARYLarge muscle fiber size imposes constraints on muscle function while imparting no obvious advantages, making it difficult to explain why muscle fibers are among the largest cell type. Johnston and colleagues proposed the 'optimal fiber size' hypothesis, which states that some fish have large fibers that balance the need for short diffusion distances against metabolic cost savings associated with large fibers. We tested this hypothesis in hypertrophically growing fibers in the lobster Homarus americanus. Mean fiber diameter was 316±11m in juveniles and 670±26m in adults, leading to a surface area to volume ratio (SA:V) that was 2-fold higher in juveniles. Na -ATPase over a broad fiber size range showed that if fibers were much smaller than those observed, maintenance of the membrane potential would constitute a large fraction of whole-animal metabolic rate, suggesting that the fibers grow large to reduce maintenance costs. However, a reaction-diffusion model of aerobic metabolism indicated that fibers in adults could attain still larger sizes without diffusion limitation, although further growth would have a negligible effect on cost. Therefore, it appears that decreased fiber SA:V makes larger fibers in H. americanus less expensive to maintain, which is consistent with the optimal fiber size hypothesis.