Identification of warm temperature acclimation‐associated 65‐kDa protein‐2 in Kumgang fat minnow Rhynchocypris kumgangensis

Abstract

Warm temperature acclimation-associated 65-kDa protein (Wap65) is known to respond to elevated water temperatures and the corresponding gene from several fish species has been cloned. Expression of Wap65 gene is induced by various physiological stresses, such as increase in water temperature, immune response and heavy metal exposure. Two isolated Wap65 genes, Wap65-1 and Wap65-2, display distinct tissue distribution and physiological functions despite high sequence homology. In a previous study, we identified the Wap65-1 gene (kmWap65-1) from Kumgang fat minnow, Rhynchocypris kumgangensis, a small freshwater fish endemic to Korea. The kmWap65-1 gene showed sequence homology with teleost Wap65-1 and mammalian hemopexin, and was highly expressed in response to increased water temperature and bacterial lipopolysaccharide (LPS) exposure. Here, we isolated kmWap65-2 from liver tissue of Kumgang fat minnow and compared the expression profiles of both kmWap65 genes following exposure to various physiological stresses, including thermal changes, bacterial challenge, and environmental toxins. Notably, while kmWap65-1 expression was significantly increased in response to high water temperature, LPS, cadmium, and iron, kmWap65-2 displayed no alterations in expression at high water temperature. However, kmWap65-2 expression was upregulated slightly in response to LPS and highly in presence of copper, bisphenol A, and estradiol. Based on the collective findings, we propose that kmWap65-1 and kmWap65-2 are multifunctional proteins with distinct functions that could serve as useful biomarkers for assessing physiological stress and associated responses in Kumgang fat minnow.

Characterization of carp seminal plasma Wap65-2 and its participation in the testicular immune response and temperature acclimation

“…This phenomenon suggests a similar mechanism of thermal acclimation within the testis and liver in carp. Our findings on the preferential induction of Wap65-1 during thermal acclimation collaborate previous observations in other fish species [19,20,22,25], but the mechanism of Wap65 action during acclimation is unknown. Weber et al [52] indicated that the warm acclimation response in fish involves increases in erythrocyte numbers and total hemoglobin content.…”

“…These data indicate the specificity of Wap65-2 to bacterial infection and inflammation within the testis, contrary to Wap65-1, which seems to be specific for temperature acclimation (see above). The involvement of Wap65-2 in the response to bacteria concurs with transcriptional control of Wap65-2 by factors derived from the immune system such as cytokines, e.g., IL-1 involved in induction of acute phase proteins, including Wap65 [25]. Analysis of the 5′ flanking region of carp Wap65 genes indicated the presence of more cytokine responsive elements and binding sites for transcription factors associated with immune response such as STAT, CEBP, TATABox, AP1, HNF, HSF, OCT1, IRF1, IRF2, CREBP for Wap65-2 as compared to Wap65-1 (Additional files 1, 9).…”

“…In fish, Wap65 was initially identified in goldfish muscle and hepatopancreas after thermal acclimation [5][6][7][8] and has since been cloned from a large number of fish [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. Notably, Wap65 function is mainly related to warm-temperature acclimation, which is most significant in eurythermal fish such as carp that live over a wide range of temperatures, from near zero to over 30 °C [5-7, 9, 10, 14, 15, 20, 22].…”

“…Notably, Wap65 function is mainly related to warm-temperature acclimation, which is most significant in eurythermal fish such as carp that live over a wide range of temperatures, from near zero to over 30 °C [5-7, 9, 10, 14, 15, 20, 22]. Besides, Wap65 is involved in the immune response [8,14,17,18,[21][22][23][24]26], intoxication [13,19,25], and embryo development [11,12,16].…”

Deiminated proteins and extracellular vesicles - Novel serum biomarkers in whales and orca

“…Hemopexin also associates with high density lipoproteins (HDL), influencing their inflammatory properties (Mehta and Reddy, 2015). In relation to aquatic animals, hemopexin has been associated with physiological stresses, including increased water temperature, immune response and heavy metal exposure in fish (Kwon and Ghil, 2017;Diaz-Rosales et al, 2014).…”