Generation of a rat monoclonal antibody specific for hsp72

Generation of Rat Monoclonal Antibodies Against a Deubiquitinase, Ovarian Tumor Domain-Containing Protein 1

Ovarian tumor domain-containing protein 1 (OTUD1), an OTU-family deubiquitinating enzyme, has been reported to be involved in cancer progression through the regulation of p53 and SMAD7. However, the precise pathophysiological functions of OTUD1 remain elusive. Here, we report the establishment of OTUD1-specific monoclonal antibodies (mAbs), using the rat medial iliac lymph node method. The generated antibodies recognize the N-terminal portion (aa. 1-290) of human and mouse OTUD1 proteins. In addition, immunofluorescent staining and subcellular fractionation analyses using these antibodies indicated that OTUD1 is predominantly localized in the cytosol. Thus, these mAbs can be further used to elucidate cellular functions of OTUD1 and its involvement in processes such as cancer progression.

Generation of Rat Monoclonal Antibodies Specific for DZIP3

DAZ interacting zinc finger 3 (DZIP3), an RNA-binding RING-type ubiquitin ligase, has been reported to be involved in multiple physiological functions, including the regulation of chemokine- or estradiol-induced gene expression, self-renewal, and maintaining pluripotency in mouse embryonic stem cells. However, the precise cellular functions of DZIP3 remain elusive. In this study, we report the establishment of DZIP3-specific monoclonal antibodies (MAbs), using the rat medial iliac lymph node method. In immunoblotting analyses, our antibodies detected endogenous human and mouse DZIP3. In addition, immunoprecipitation analyses revealed the availability of these antibodies for human or mouse DZIP3. Thus, these MAbs will be available to elucidate cellular functions of DZIP3.

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

Heat shock protein 70 (Hsp70) is an evolutionarily well-conserved molecular chaperone involved in several cellular processes such as folding of proteins, modulating protein-protein interactions, and transport of proteins across the membrane. Binding partners of Hsp70 (known as "clients") are identified on an individual basis as researchers discover their particular protein of interest binds to Hsp70. A full complement of Hsp70 interactors under multiple stress conditions remains to be determined. A promising approach to characterizing the Hsp70 "interactome" is the use of protein epitope tagging and then affinity purification followed by mass spectrometry (AP-MS/MS). AP-MS analysis is a widely used method to decipher protein-protein interaction networks and identifying protein functions. Conventionally, the proteins are overexpressed ectopically which interferes with protein complex stoichiometry, skewing AP-MS/MS data. In an attempt to solve this issue, we used CRISPR/Cas9-mediated gene editing to integrate a tandem-affinity (TAP) epitope tag into the genomic locus of HSC70. This system offers several benefits over existing expression systems including native expression, no requirement for selection, and homogeneity between cells. This cell line, freely available to chaperone researchers, will aid in small and large-scale protein interaction studies as well as the study of biochemical activities and structure-function relationships of the Hsc70 protein.