Viral infection is the primary cause of respiratory morbidity in cystic fibrosis (CF) infants. Here, we identify that host factors allow increased virus replication and cytokine production, providing a mechanism for understanding the severity of virus disease in CF. Increased virus is due to lack of nitric oxide synthase 2 (NOS2) and 2', 5' oligoadenylate synthetase (OAS) 1 induction in response to virus or IFNgamma. This can be attributed to impairment of activation of signal transducer and activator of transcription (STAT)1, a fundamental component to antiviral defense. NO donor or NOS2 overexpression provides protection from virus infection in CF, suggesting that NO is sufficient for antiviral host defense in the human airway and is one strategy for antiviral therapy in CF children.

The phosphoprotein (P) gene of rabies virus (CVS strain) was cloned and expressed in bacteria. The purified protein was used as the substrate for phosphorylation by the protein kinase(s) present in cell extract prepared from rat brain. Two distinct types of protein kinases, staurosporin sensitive and heparin sensitive, were found to phosphorylate the P protein in vitro by the cell extract. Interestingly, the heparin-sensitive kinase was not the ubiquitous casein kinase II present in a variety of cell types. Further purification of the cell fractions revealed that the protein kinase C (PKC) isomers constitute the staurosporin-sensitive kinases ␣, ␤, ␥, and , with the PKC␥ isomer being the most effective in phosphorylating the P protein. A unique heparin-sensitive kinase was characterized as a 71-kDa protein with biochemical properties not demonstrated by any known protein kinases stored in the protein data bank. This protein kinase, designated RVPK (rabies virus protein kinase), phosphorylates P protein (36 kDa) and alters its mobility in gel to migrate at 40 kDa. In contrast, the PKC isoforms do not change the mobility of unphosphorylated P protein. RVPK appears to be packaged in the purified virions, to display biochemical characteristics similar to those of the cell-purified RVPK, and to similarly alter the mobility of endogenous P protein upon phosphorylation. By site-directed mutagenesis, the sites of phosphorylation of RVPK were mapped at S 63 and S 64 , whereas PKC isomers phosphorylated at S 162 , S 210 , and S 271 . Involvement of a unique protein kinase in phosphorylating rabies virus P protein indicates its important role in the structure and function of the protein and consequently in the life cycle of the virus.Like viruses belonging to the rhabdovirus and paramyxovirus family, Rabies virus (RV), a member of Lyssavirus genus, contains a linear nonsegmented RNA genome of negative polarity. The ribonucleoprotein (RNP) complex contains the genome RNA enwrapped by the nucleocapsid protein (N) and the RNA polymerase, which contains a large protein (L) and the phosphoprotein (P) (1). Both L and P proteins of RV, like the corresponding proteins in rhabdoviruses and paramyxoviruses, are involved in the transcription and replication of the genome RNA (1, 46). Although the L proteins of this class of viruses show significant similarity in amino acid sequence, the P proteins appear to be highly divergent and nonhomologous. However, all P proteins are structurally similar in being highly acidic and phosphorylated and in playing a common vital role as transcription factors for the function of the corresponding L proteins. The P proteins, in addition to providing the transcription function of the L protein, appear to play an important role in the replicative process as well (19,22,28,34,36). In this role, the P protein forms a complex intracellularly with the N protein to impart an undefined replication-competent form to the latter which enables it to encapsidate nascent RNA chains during the replicative reaction ...

Mammalian spermiogenesis is marked by the initial disruption of the nuclear-histone-DNA complex by the transition proteins for ultimate replacement with protamines. The genes for three of these low molecular weight basic nuclear proteins exist as a single linear array of PRM1, PRM2, and TNP2 on human chromosome 16p13.2. To begin to address the mechanism governing their transcriptional potentiation, a region of approximately 40 kilo-bases of the human genome encompassing these genes was introduced into the germ line of mice. Fluorescence in situ hybridization and Southern analysis showed that this segment of the human genome integrated into independent chromosomal sites while maintaining its fidelity. Transcript analysis demonstrated that the expression of the endogenous mouse protamine Prm1 and Prm2 genes as well as the mouse transition protein Tnp2 gene were expressed along with their human transgene counterparts. The pattern of expression of these transgenic human genes within this multigenic cluster faithfully represented that observed in vivo. In addition, all members of this transgenic gene cluster were expressed in proportions similar to those in human testis. Copy number-dependent and position-independent expression of the transgenic construct demonstrated that the corresponding biological locus was contained within this segment of the human genome. Furthermore, DNase I sensitivity established that in sperm the human PRM1-->PRM2-->TNP2 genic domain was contained as an approximately 28.5-kilobase contiguous segment bounded by an array of nuclear matrix associated topoisomerase II consensus sites. This is the first description of a multigenic male gamete-specific domain as a fundamental gene regulatory unit. A model of haploid-specific gene determination is presented.

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