Dynamic remodeling of the interactomes of Nematostella vectensis Hsp70 isoforms under heat shock

Abstract

Heat shock protein 70s (Hsp70s) are a highly conserved class of molecular chaperones that fold a large proportion of the proteome. Nematostella vectensis (Nv) is an estuarine sea anemone that has emerged as a model species to characterize molecular responses to physiological stressors due to its exposure to diverse, extreme abiotic conditions. Previous transcriptional data has shown dramatic differences among expression profiles of three NvHsp70 isoforms (NvHsp70A, B and D) under stress but it is unknown if, and to what extent, the client proteins for these chaperones differ. In order to determine client specificity, NvHsp70A, B and D were expressed in Saccharomyces cerevisiae budding yeast lacking native Hsp70 and interacting proteins for each Hsp70 were determined with mass spectrometry in yeast ambient and heat shock conditions. Our analyses showed <50% of identified interacting proteins were common to all three anemone Hsp70s and 3-18% were unique to an individual Hsp70. Mapping of temperature induced interactions suggest that under stress a proportion of clients are transferred from NvHsp70A and NvHsp70D to NvHsp70B. Together, these data suggest a diverse set of interacting proteins for Hsp70 isoforms that likely determines the precise functions for Hsp70s in organismal acclimation and potentially adaptation.

HSP70/DNAJ Family of Genes in the Brown Planthopper, Nilaparvata lugens: Diversity and Function

“…However, the accumulated studies have revealed the diversity of HSP70s. It has been demonstrated that different HSP70 isoforms have unique cochaperone and client interactors, and functional diversity is defined by the affinities for specific cochaperones [ 37 , 38 , 39 ]. Together, our discoveries may offer novel clues to explore the relationships between HSP70 family members and uncover the underlying mechanism of HSP70s in contributing to oogenesis, embryogenesis, and the thermal tolerance of eggs.…”

Rapid deacetylation of yeast Hsp70 mediates the cellular response to heat stress

“…These isoforms appear to have high functional overlap, especially as yeast can maintain viability upon loss of any three Ssa isoforms 24 . Recent evidence suggests that these Hsp70 isoforms are not fully redundant and have specialized roles dictated though unique clientomes 24,57,58 . Although 3 of 4 lysines are conserved in the Ssa proteins, the heat inducible Ssa3 and Ssa4 contain an alanine at position 562 instead of lysine, and thus cannot undergo acetylation at this site.…”

Dataset of Nematostella vectensis Hsp70 isoform interactomes upon heat shock

“…Lastly, NvHsp70D interacted with a total of 639 (55%), of which 38 (3%) were unique to the D isoform. NvHsp70A and NvHsp70B shared 240 interactors (21%), whereas NvHsp70A and NvHsp70D only shared 21 interactors (1.8%) and NvHsp70B and NvHsp70D 31 interactors [1].…”