[Proceedings, Annual Meeting of the Laboratory of Tumor Cell Biology (1990 : Bethesda, Maryland)]

MUTATIONS IN THE ZINC FINGER-LIKE REGION OF HIV-1 NUCLEOCAPSID YIELD NON-INFECTIOUS
PARTICLES DEFICIENT IN GENOMIC RNA.
Robert J. Gorelick', Stephen M. Nigida, Jr.', Julian W. Bess, Jr.', Larry 0. Arthur'
Louis E. Henderson an1 Alan Rein. 'AIDS Vaccine Program, Program Resources Inc.,
and 2Laboratory of Molecular Virology and Carcinogenesis, ABL-Basic Research Program,
NCI-FCRDC, Frederick, Maryland 21701-1013.
In the nucleocapsid domain of the Gag protein, all retroviruses contain at least one
copy of a zinc finger-like sequence (Cys-X2-CyS-X4-His-X4-Cys) which is involved in
the recognition of genomic RNA. We have generated several point and deletion
mutations in this motif in HIV-1 and Moloney MuLV. These virus particles appear to
contain the normal complement of viral proteins as determined by a number of
criteria. These mutant virions are, however, deficient in genomic RNA. No infectivity
could be detected in the mutant HIV-1 particles under conditions that yielded 10
infectious units in the wild type. Similar results were obtained in the MuLV mutants.
The HIV-1 nucleocapsid protein contains two zinc finger-like sequences, and mutation
of either reduces RNA packaging and infectivity. Also, one mutant capable of
packaging approximately 20% of the viral RNA remained non-infectious indicating the
nucleocapsid protein was involved in some other function vital for infection. HIV1 mutants of this type may have important applications, including non-hazardous
reagents for research, immunogens in vaccine and immunotherapy studies, and
diagnostic reagents. In addition, the extreme conservation of the cysteine array
among retroviruses may present possibilities for developing universal diagnostic
reagents while the exquisite sensitivity of the virus to changes in the array
suggests that the array is a potential target for the development of antiviral drugs.
This work is sponsored in part by the NCI, DHHS, under contract NO. N01-CO-74101 with
ABL, NO. N01-CO-74102 with PRI, and NIH, Individual National Research Service Award
NO. 5 F32 AIO 7684-02.