ASC/TMS1 Overexpression Lysate

HEK293T cells in 10-cm dishes were transiently transfected with a non-lipid polymer transfection reagent specially designed and manufactured for large volume DNA transfection. Transfected cells were cultured for 48hrs before collection. The cells were lysed in modified RIPA buffer (25mM Tris-HCl pH7.6, 150mM NaCl, 1% NP-40, 1mM EDTA, 1xProteinase inhibitor cocktail mix, 1mM PMSF and 1mM Na3VO4, and then centrifuged to clarify the lysate. Protein concentration was measured by BCA protein assay kit.

ASC (apoptosis-associated speck-like protein containing a CARD), also known as TMS1 (target of methylation-induced silencing), was first identified in 1999 as a protein that forms aggregates, or specks, during retinoic acid-induced apoptosis in a human leukemia cell line (1). Furthermore, it was discovered to have a role as a tumor suppressor as methylation silences ASC/TMS1 expression in many tumors (2-5). ASC/TMS1 is synthesized as a 195-amino acid (aa) protein with a theoretical weight of 22 kDa. Structurally the protein contains a N-terminal PYD (pyrin domain) and C-terminal CARD (caspase-recruitment domain) (1-4). Historically, CARD and PYD-containing proteins are known to have crucial functions in regulating apoptosis and immune response pathways (2-5). Furthermore, mutations in many CARD and PYD-containing proteins have been linked to various cancers and inflammatory diseases (2-5). Given its immune response role, it is not surprising that ASC/TMS1 is typically highly expressed in immune cells, specifically in neutrophils and cells of the macrophage/monocyte lineage (5). Additionally, it is expressed in many normal epithelial cell types (4,5).

In regard to immune and inflammatory response, ASC/TMS1 is involved in inflammasome function (3-4). The inflammasome is a multiprotein complex that responds to cellular stress or pathogens and activates inflammatory responses. Specifically, ASC/TMS1 helps assemble the NLRP3 inflammasome complex which then activates caspase-1, followed by stimulation of proinflammatory cytokines including IL-1b and IL-18 (3-4). In terms of the role in regulating apoptosis, multiple studies have revealed that the ASC/TMS1 gene is hypermethylated in many cancers including breast, lung, glioblastomas, and melanomas (2-5). The increased methylation results in decreased gene expression, or silencing, allowing those cancer cells to escape apoptosis (2-5).

References

1. Masumoto, J., Taniguchi, S., Ayukawa, K., Sarvotham, H., Kishino, T., Niikawa, N., Hidaka, E., Katsuyama, T., Higuchi, T., & Sagara, J. (1999). ASC, a novel 22-kDa protein, aggregates during apoptosis of human promyelocytic leukemia HL-60 cells. The Journal of biological chemistry, 274(48), 33835-33838. https://doi.org/10.1074/jbc.274.48.33835

2. McConnell, B. B., & Vertino, P. M. (2004). TMS1/ASC: the cancer connection. Apoptosis: an international journal on programmed cell death. https://doi.org/10.1023/B:APPT.0000012117.32430.0c

3. Salminen, A., Kauppinen, A., Hiltunen, M., & Kaarniranta, K. (2014). Epigenetic regulation of ASC/TMS1 expression: potential role in apoptosis and inflammasome function. Cellular and molecular life sciences : CMLS. https://doi.org/10.1007/s00018-013-1524-9

4. Protti, M. P., & De Monte, L. (2020). Dual Role of Inflammasome Adaptor ASC in Cancer. Frontiers in cell and developmental biology. https://doi.org/10.3389/fcell.2020.00040

5. Parsons, M. J., & Vertino, P. M. (2006). Dual role of TMS1/ASC in death receptor signaling. Oncogene. https://doi.org/10.1038/sj.onc.1209684

This product is for research use only and is not approved for use in humans or in clinical diagnosis. Lysates are guaranteed for 6 months from date of receipt.

Array NBL1-15016

• ASC/TMS1 Antibodies
• ASC/TMS1 Lysates
• ASC/TMS1 Proteins