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Updated: Feb 20, 2026
Identification of Nucleolar Factors During HIV-1 Replication Through Rev Immunoprecipitation and Mass Spectrometry
Published on: June 26, 2019
Differential interaction between human and murine Crm1 and lentiviral Rev proteins
Yan Yue1, Ayse K Coskun1, Navneet Jawanda1
1Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, United States.
Abstract:
Mice have multiple obstacles to HIV replication, including a block of unspliced and partially spliced viral mRNA nuclear export. In human, Rev binds to the Rev-response element and human (h) Crm1, facilitating nuclear export of RRE-containing viral RNAs. Murine (m) Crm1 is less functional than hCrm1 in this regard. Here we demonstrated that in biochemical experiments mCrm1 failed to interact with HIV Rev whereas hCrm1 did. In genetic experiments in human cells, we observed a modest but significant differential effect between mCrm1 and hCrm1, which was also true of other lentiviral Revs tested. Triple mutant hCrm1 P411T-M412V-F414S behaved similarly to mCrm1, whereas mCrm1 with T411P-V412M-S414F regained some activity, although contribution of additional residues to its function can not be excluded. Similar results were observed in murine cells. This suggests a differential interaction between hCrm1 and mCrm1 and many lentiviral Revs, which may partially explain the HIV replicative defect in mice.
Insights
Murine Crm1 is less effective than human Crm1 at exporting HIV RNA, hindering viral replication in mice. Mutating human Crm1 mimics murine Crm1's reduced function.
Area of Science:
- Virology
- Molecular Biology
- Immunology
Background:
- HIV replication is blocked in mice due to impaired nuclear export of viral RNA.
- The Rev protein facilitates nuclear export of viral RNA by binding to the Rev-response element and human (h) Crm1.
Purpose of the Study:
- To investigate the differential function of murine (m) Crm1 compared to human (h) Crm1 in HIV Rev-mediated nuclear export.
- To identify specific residues responsible for the functional differences between mCrm1 and hCrm1.
Main Methods:
- Biochemical experiments to assess the interaction between HIV Rev and mCrm1 versus hCrm1.
- Genetic experiments in human and murine cells using wild-type and mutant Crm1 proteins.
Main Results:
- Biochemical assays showed mCrm1 failed to interact with HIV Rev, unlike hCrm1.
- Genetic studies revealed a significant differential effect between mCrm1 and hCrm1 on lentiviral Rev function.
- Mutagenesis studies identified specific amino acid substitutions in hCrm1 that mimicked mCrm1's reduced activity, and vice versa.
Conclusions:
- Differential interactions between Crm1 proteins from different species and lentiviral Rev proteins contribute to the HIV replication defect in mice.
- Specific amino acid residues in Crm1 are critical for its interaction with Rev and nuclear export function.
