Ssb Knockout CHO-K1 Cell Line

The Ssb Knockout CHO-K1 Cell Line is a CRISPR/Cas9-engineered Chinese hamster ovary model in which the endogenous Ssb gene has been disrupted to eliminate functional SSB/La expression. This stable in vitro knockout system is generated in CHO-K1, an epithelial-like ovary cell line from Chinese hamster that is extensively used for mammalian cell engineering and mechanistic studies. The model is intended for investigation of RNA-binding protein function in a well-characterized host background that supports molecular, biochemical, and cell-based analysis.

CHO-K1 is a clonally derived Chinese hamster ovary line broadly used in transfection, recombinant protein production, genome engineering, glycosylation research, and biomanufacturing process development. Its robust growth properties and compatibility with genetic manipulation have made it a standard mammalian host for studying gene function, RNA metabolism, and stress-associated cellular phenotypes. Because CHO-K1 is widely adopted across cell biology and biotechnology workflows, targeted gene disruption in this background provides a practical platform for linking genotype to RNA processing outputs, translational control, and broader host-cell behavior.

SSB encodes the La autoantigen, a conserved RNA-binding protein that binds the 3′ oligo(U) termini of nascent RNA polymerase III transcripts and protects these RNAs from exonucleolytic degradation. SSB acts downstream of RNA polymerase III transcriptional activity and is regulated in part by cellular stress, AKT1, MTOR, and casein kinase 2-associated signaling contexts. At the molecular level, SSB interacts with newly synthesized pre-tRNAs, 5S rRNA precursors, U6 snRNA precursors, and Y RNAs, and functions in networks that include the POLR3 complex, POLR3A, POLR3B, BRF1, TFIIIB, RNASEP, ELAC2, and TROVE2/Ro60. Through these interactions, SSB promotes correct RNA folding, maturation, ribonucleoprotein assembly, and RNA quality control, with downstream consequences for RNA stability and translation efficiency. These functions are directly relevant to autoimmune antigen biology, RNA processing disorders, cancer-associated translational reprogramming, and viral host-factor studies.

In CHO-K1 cells, loss of Ssb provides a useful system for examining how impaired Pol III transcript handling influences epithelial-like mammalian host-cell physiology. Disruption of this RNA chaperone is expected to alter pre-tRNA maturation, small noncoding RNA biogenesis, and translation-related homeostasis, thereby enabling analysis of pathway dependency between RNA processing machinery and host-cell stress adaptation. In a production-relevant mammalian cell background, this model can also support studies of how RNA quality control interfaces with growth, transfection response, and engineered cell-state regulation.

This knockout cell line is suitable for targeted studies of RNA processing and translational regulation using western blotting, RT-qPCR, northern blotting, RNA-seq, and small RNA-seq to measure changes in SSB-dependent transcript classes and maturation intermediates. Researchers can apply RNA immunoprecipitation or co-immunoprecipitation to interrogate altered associations with TROVE2, Pol III-linked factors, or RNA granule components, and use immunofluorescence to examine subcellular redistribution under basal or stress conditions. Functional consequences of Ssb loss may also be explored through polysome profiling, tRNA processing assays, cell growth assays, and stress-response assays in workflows relevant to autoimmune antigen research, host-factor biology in infection models, and CRISPR-based functional genomics. Researchers may contact Ascent Research for additional technical information, product details, or related gene-edited cell models.