We appreciate Dr. Cattoretti for his interest in our work (1). As Dr. Cattoretti showed in B cells (2), the 9E10 may detect other protein. In a previous communication, he also mentioned that the 9E10 can detect the AKLVSE epitope in addition to the original epitope of QKLISEEDL (Validation of a New Recombinant Human anti-c-Myc Tag Antibody, https://www.pepperprint.com/updates/application-notes-and-posters/).3 Thus, we searched the AKLVSE sequence using Blastp to find which protein has the sequence. We found that the 9E10 might recognize two other proteins besides MYC (i.e. MRVI1 and CCDC152) (Fig. 1). Interestingly, MRVI1 is reported as “encodes a protein with homology to a lymphoid-restricted membrane protein Jaw1” (3). Thus, we may be able to expect that the 9E10 might detect MRVI1 in B cells (2). When we analyzed the expression of MRVI1 and CCDC152, we found that their expressions are not so critical in human reprogramming (4). Collectively, although the 9E10 may not be so specific to MYC, we think that our results represent proper MYC expression in human reprogramming.
Figure 1.
Capture of the result of Blastp search on AKLVSE sequence. Because of space limitations, some representative results of the top scores are selected.
In addition, we reviewed our results again to check whether the data related to MYC could affect our conclusions. However, because our main conclusions are not directly related to the MYC expression, and the 9E10 may specifically detect MYC in our experimental setting, we think that our report (5) will not cause any serious confusion for readers.
Footnotes
The authors declare that they have no conflicts of interest with the contents of this article.
Please note that the JBC is not responsible for the long-term archiving and maintenance of this site or any other third party hosted site.
References
- 1. Cattoretti G. (2019) Specificity of anti-MYC antibodies. J. Biol. Chem. 294, 10.1074/jbc.L119.011910 10.1074/jbc.L119.011910 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2. Cattoretti G. (2013) MYC expression and distribution in normal mature lymphoid cells. J. Pathol. 229, 430–440 10.1002/path.4141 [DOI] [PubMed] [Google Scholar]
- 3. Shaughnessy J. D. Jr., Largaespada D. A., Tian E., Fletcher C. F., Cho B. C., Vyas P., Jenkins N. A., and Copeland N. G. (1999) Mrvi1, a common MRV integration site in BXH2 myeloid leukemias, encodes a protein with homology to a lymphoid-restricted membrane protein Jaw1. Oncogene 18, 2069–2084 10.1038/sj.onc.1202419 [DOI] [PubMed] [Google Scholar]
- 4. Tanaka Y., Hysolli E., Su J., Xiang Y., Kim K. Y., Zhong M., Li Y., Heydari K., Euskirchen G., Snyder M. P., Pan X., Weissman S. M., and Park I. H. (2015) Transcriptome signature and regulation in human somatic cell reprogramming. Stem Cell Reports 4, 1125–1139 10.1016/j.stemcr.2015.04.009 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5. Im I., Son Y. S., Jung K. B., Kang I., Teh B-e Lee K-B, Son M.-Y., and Kim J. (2019) Mass cytometry-based single-cell analysis of human stem cell reprogramming uncovers differential regulation of specific pluripotency markers. J. Biol. Chem. 294, 18547–18556 10.1074/jbc.RA119.009061 [DOI] [PMC free article] [PubMed] [Google Scholar]