Mx1^r
Spontaneous Allele Detail

Summary

• Symbol: Mx1^r
• Name: MX dynamin-like GTPase 1; myxovirus resistance
• MGI ID: MGI:3715151
• Gene: Mx1 Location: Chr16:97248235-97264106 bp, - strand Genetic Position: Chr16, 57.46 cM, cytoband C4
• Alliance: Mx1^r page

Mutation origin

• Strain of Origin: multiple strains

Mutation description

• Allele Type: Spontaneous
• Mutation: Not Applicable
• A2G, SL/NiA, T9 and CAST/Ei strains produce the MX1 protein conferring resistance to myxoviruses. (J:9452)

Find Mice (IMSR)

• Mouse strains and cell lines available from the International Mouse Strain Resource (IMSR)
• Carrying this Mutation: Mouse Strains: 1 strain available Cell Lines: 0 lines available
• Carrying any Mx1 Mutation: 80 strains or lines available

Notes

The Mx genes determine resistance to the lethal effects of various myxoviruses including neurotropic avian influenza A virus injected intracerebrally, pneumotropic strains injected intranasally, and a hepatotropic strain injected intraperitoneally (J:5645, J:13136). Resistance is not dependent on presence of the thymus and is not abolished by immunosuppression or by inhibitors of macrophage function (J:5735, J:5478, J:5645). Resistance is specific for the orthomyxoviruses (J:6265). It is dependent on the presence of interferon-alpha and -beta but not -gamma (J:7365).

The resistance allele at the Mx1 locus, under induction by alpha/beta interferon, produces the 75 kDa protein MX-1, which confers resistance to the influenza virus, in the nuclei of cells carrying the allele. Susceptibility alleles do not produce the protein (J:8273). The protein is located in the nucleus (J:7703) and produces its antiviral effect by preventing synthesis of viral mRNA in the nucleus (J:7992). Nuclear localization is necessary for anti-influenza virus activity (J:1417), but mutations induced in Mx1 showed that nuclear position was not sufficient for the effect; mutations in several domains can cause its loss (J:11840). The MX-1 protein is a GTPase containing a GTP binding domain (J:1417) and this binding core is also necessary (J:21243).

Resistance is expressed by macrophages and other cells in vitro (J:6649, J:5940) but could not be transferred to susceptible animals by transfer of macrophages from resistant mice (J:6149).

Resistance to infection with two tick-borne viruses, Thogoto virus (J:8273) and Dhori virus (J:27760), is also conferred by Mx1^r.

The Mx1^r allele occurs only in strains A2G, SL/NiA, and T9, the latter being a strain derived from an influenza-resistant wild stock, and CAST/Ei, derived from Mus musculus castaneus. Most inbred strains, including C57BL/6J, C3H/HeJ, and BALB/cJ, carry an influenza susceptible Mx1^s1 allele which produces mRNA lacking exons 9, 10, and 11 of the Mx1^r allele. This large deletion apparently renders the protein incapable of providing resistance to influenza. The CBA/J, CE/J, I/LnJ, and PERA/Ei strains, also susceptible to the virus, have another form of the Mx1^s2 allele in which there is a nonsense mutation (J:9452).

Interferon is induced by viral infection and in turn induces the Mx protein (J:7703). Although some interferon-induced genes respond directly to virus invasion as well as indirectly through induction by virus-induced interferon, this primary response is very weak for the MX-1 protein in response to either influenza or Newcastle disease viruses (J:1892).

References

• Original: J:13136 LINDENMANN J, INHERITANCE OF RESISTANCE TO INFLUENZA VIRUS IN MICE. Proc Soc Exp Biol Med. 1964 Jun;116:506-9
• All: 31 reference(s)