Cloning and expression analysis of a heat shock protein 90 β isoform gene from the gills of Wuchang bream (Megalobrama amblycephala Yih) subjected to nitrite stress

Abstract

ABSTRACT. Heat shock protein 90 (HSP90), a highly conserved and multi-functional molecular chaperone, plays an essential role in cellular metabolism and stress response. In this study, HSP90 cDNA named MaHSP90 was cloned from Wuchang bream (Megalobrama amblycephala) gills by using rapid amplification of cDNA ends. The fulllength MaHSP90 cDNA is 2674 bp and consists of a 3',5'-untranslated region and a 2250-bp open reading frame encoding a 750-amino acid long protein. Identity analysis revealed that the amino acid sequence of MaHSP90 is highly conserved. Homology analysis and structure comparison further indicated that MaHSP90 should be the β isoform member of the HSP90 family. MaHSP90 mRNA was ubiquitously expressed in the liver, heart, muscle, gill, intestine, kidney, and brain. The MaHSP90 mRNA levels under nitrite stress were analyzed using real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR); the mRNA levels significantly increased at 3, 6, and 12 h after nitrite exposure in the gills and then stabilized between 24 and 48 h. Furthermore, a similar relationship between mRNA expression (qRT-PCR) and HSP90 protein levels (densitometric band analysis) was found. Transcriptional analysis of caspase-8 and caspase-9 expression in the gills of juvenile M. amblycephala after a 48-h exposure to nitrite suggested that MaHSP90 expression is related positively with nitriteinduced apoptosis. Fish exposed to nitrite also showed gill damage. Our results suggest that MaHSP90 mRNA is constitutively expressed in various tissues and inducible in the gills under nitrite stress, suggesting its important role in nitrite stress response.

Effects of nitrite exposure on haematological parameters, oxidative stress and apoptosis in juvenile turbot (Scophthalmus maximus)

“…Guo et al (2013) estimated the caspase-3 mRNA level in nitrite-treated Litopenaeus vannamei and found nitrite led to activation of caspases and initiation of hemocytes apoptosis. In vivo study showed that nitrite exposure induced increases in mRNA levels of caspase -8 and caspase -9 in the gills of juvenile Megalobrama amblycephala (Sun et al, 2014b). In the present study, we also discovered the ascensions in mRNA levels of caspases -3, -7, and -9 in gills of turbot exposed to nitrite.…”

“…In aquatic animal, nitrite exposure also promoted apoptosis. Sun et al (2014b) reported that nitrite exposure induced the transcription of apoptosis-related genes (caspase-8 and caspase-9) and contributed to apoptosis in gills of juvenile Megalobrama amblycephala. Similarly, nitrite-induced haemocyte apoptosis was observed in Litopenaeus vannamei, Penaeus monodon and Macrobrachium rosenbergii (Guo et al, 2013;Xian et al, 2011;Zhang et al, 2015).…”

Mitochondria-rich cells changes induced by nitrite exposure in tambaqui (Colossoma macropomum Cuvier, 1818)

“…Evidences indicate that necrosis is the main cell death program triggered when ATP levels drop rapidly after NO 2 -stress (Leist et al 1997, Brown and Borutaite 2002, Leist et al 1999). In opposition to other studies, few cells were demised from epithelia by apoptosis, however, this cell death program has been reported after NO 2 -intoxication in fish (Jia et al 2015, Sun et al 2014.…”

Research Article Heat shock genes in the stingless bee <i>Melipona interrupta</i> (Hymenoptera, Meliponini)

“…LGTIA(K/R)SGT, IGQFGVGFYS(A/C)(Y/F)LVA(E/D), IKLYVRRVFI and GVVDS(E/D)DLPLN(I/V)SER. Many other studies have also confirmed these signature sequences in insects (Hai-Hong et al, 2014;Chen et al, 2014;Sun et al, 2015;Qiao et al, 2015). Moreover, the two conserved motifs MEEVD in the C-terminal part and the central domain GXXGXG in all HSP90 are also common in HSP70 (Gupta, 1995).…”

“…HSP90 proteins are among the most abundant and well-conserved proteins, corresponding to 1-2% of the total proteins in a cell under normal conditions (Sun et al, 2015;Qiao et al, 2015;Lu et al, 2016). HSP90 has an important role in cell homeostasis, acting in fundamental cell activities, such as protein folding and refolding and thermal shock stress as well as other physiological functions, such as cell signaling and protein degradation (Sun et al, 2015;Lu et al, 2016).HSP90 presents two isoforms in the cell: an inducible form (HSP90A) and a constitutive form (HSP90Beta) (Sun et al, 2015). However, only one isoform is present in many insect species (Lu et al, 2016).…”