Heat Shock Protein 40 (HSP40) in Pacific White Shrimp (Litopenaeus vannamei): Molecular Cloning, Tissue Distribution and Ontogeny, Response to Temperature, Acidity/Alkalinity and Salinity Stresses, and Potential Role in Ovarian Development

Abstract

Heat shock proteins (HSPs), a family of conserved proteins that are produced by cells in response to stresses, are known as molecular chaperones with a range of housekeeping and cellular protective functions. The 40 kD heat shock protein (HSP40) is a co-chaperone for HSP70 in the regulation of ATP hydrolysis. Unlike its well-documented cofactor HSP70, little is currently known regarding the biological functions of HSP40 in crustacean species such as penaeid shrimp. In the present study, the cDNA encoding HSP40 (Lv-HSP40) was identified from the Pacific white shrimp Litopenaeus vannamei, a highly significant commercial culture species. The structural organization indicates that Lv-HSP40 belongs to the type-I HSP40s. The muscle, gill, and hepatopancreas are the main sites of Lv-HSP40 transcript expression. Within these tissues, Lv-HSP40 mRNA were predominantly exhibited in the myocytes, epithelial cells and hepatopancreatic cells, respectively. Under acute thermal stress in the culture environment, Lv-HSP40 transcript levels are significantly induced in these three tissues, while low pH stress only upregulates Lv-HSP40 mRNA in the hepatopancreas and gill. During ontogenesis, Lv-HSP40 transcript levels are high at early embryonic stages and drop sharply at late embryonic and early larval stages. The ovary is another major organ of Lv-HSP40 mRNA expression in female shrimp, and Lv-HSP40 transcripts were mainly presented in the follicle cells but only weekly detected in the oocytes. Ovarian Lv-HSP40 mRNA levels increase continuously during gonadal development. Silencing of the Lv-HSP40 gene by RNA interference may effectively delay ovarian maturation after unilateral eyestalk ablation. The roles of Lv-HSP40 in ovarian development are speculated to be independent of its cofactor HSP70, and the vitellogenesis factor vitellogenin (Vg) and vitellogenin receptor (VgR). Our study, as a whole, provides new insights into the roles of HSP40 in multiple physiological processes in L. vannamei: (1) HSP40 is a responding factor during stressful conditions; and (2) HSP40 participates in embryonic and ovarian development.

Transcriptomic analysis of female and male gonads in juvenile snakeskin gourami (Trichopodus pectoralis)

“…DnaJ homolog, subfamily C, member 25 (dnajc25) encodes a protein belong to heat shock protein (HSP) 40 subfamily C that functions as co-chaperone by binding to HSP 70 to stimulate adenosine triphosphate hydrolysis. In the Pacific white shrimp (Litopenaeus vannamei), high levels of HSP 40 transcripts were detected in ovary, and it was suggested to play important role in ovarian development 21,22 . Zona pellucida sperm-binding protein (zp) is one of the major proteins of egg envelopment and is essential for sperm penetration and fusion of the plasma membrane to prevent polyspermy 23 .…”

Phloroglucinol Treatment Induces Transgenerational Epigenetic Inherited Resistance Against Vibrio Infections and Thermal Stress in a Brine Shrimp (Artemia franciscana) Model

“…However, after a challenge with V. parahaemolyticus or V. harveyi , it appears that both HSP70 and HSP90 mRNA followed similar expression patterns at different time points and different generations. Increased levels of HSP70 may not be the only factor for transgenerational increased resistance of the animals against pathogenic challenge, and other molecular chaperones, such as HSP40, HSP60 , and HSP90 , may play a bigger role (67, 68). Our results suggest that application of phloroglucinol has an effect on keeping signaling molecules and more importantly HSP70 and HSP90 mRNA primed for a more efficient response during the stressful condition (21, 69).…”

Multi-omic approach provides insights into osmoregulation and osmoconformation of the crab Scylla paramamosain

“…Most of HSPs function as molecular chaperones to assist correct folding of new proteins or refold proteins damaged by cellular stress 67 . Many examples on the involvement of HSPs in hypo-osmotic stress have been documented in decapods, such as L. vannamei 69 , Homarus americanus 70 and E. sinensis 15 , as well as copepods 65 , 71 and fishes 68 , 72 , though the specific HSP genes often differ among studies. In our study, three HSP genes (ENPL, CH60 and HSP7C) were upregulated in the 5 ppt/6 h group, of which HSP7C was reported to participate in salinity stress response of E. sinensis 15 .…”