Endogenous epitope tagging of heat shock protein 70 isoform Hsc70 using CRISPR/Cas9

Genome-Wide Analysis of HSP70 Family Protein in Vigna radiata and Coexpression Analysis Under Abiotic and Biotic Stress

Heat shock protein 70 (Hsp70), a 70-kDa protein, also known as a molecular chaperone, is highly conserved. It plays a major role in cellular functions such as protein folding, regulation of protein degradation, translocation of proteins across membranes, receptor signaling, and protein assembly or disassembly. Vigna radiata is an important legume crop with available whole-genome sequence, but no such study on the HSP70 family is reported. A total of 32 V. radiate HSP70s (Vr-HSP70s) were identified and described. They are phylogenetically clustered into four subgroups. Vr-HSP70s show variations in intron/exon organization. This indicates that introns may play an essential role in gene regulating. The coexpression analysis of Vr-HSP70s revealed that these genes were involved in both abiotic and biotic stresses. Three cytoplasmic hub genes namely Vr-HSP70-C-14, Vr-HSP70-C-29, and Vr-HSP70-C-30 were found common in both stresses. Our findings provide directions for future studies to dissect functional analysis of Vr-HSP70s in response to abiotic and biotic stresses.

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

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. BIOLOGICAL SIGNIFICANCE: Although the Hsp70 family of molecular chaperones has been studied for >50 years, it is still not fully understood why organisms encode and express many highly-similar Hsp70 isoforms. The prevailing theory is that these isoforms have identical function, but are expressed under unique cellular conditions that include heat shock to cope with increased number of unfolded/misfolded proteins. The sea anemone Nematostella vectensis encodes three Hsp70 isoforms A, B and D that when expressed in yeast demonstrate unique functionalities. This study provides the interactome of NvHsp70s A, B and D and demonstrates that Hsp70 isoforms, while highly similar in sequence, have unique co-chaperone and client interactors.

CRISPR/Cascade 9-Mediated Genome Editing-Challenges and Opportunities

Clustered Regularly Interspaced Palindromic Repeats (CRISPR) and Cascade 9 (also known as Cas9, CRISPR associated protein 9) confer protection against invading viruses or plasmids. The CRISPR/Cascade 9 system constitutes one of the most powerful genome technologies available to researchers today. So far, this technology has enabled efficient genome editing and modification in several model organisms and has successfully been used in biomedicine and biomedical engineering. However, challenges for efficient and safe genetic manipulation in several organisms persist. Here, we review functional approaches and future challenges associated with the use of the CRISPR/Cascade 9 genome editing system and discuss opportunities, ethical issues and future directions within this field.