Disease relevance of C1

• Nucleotide sequence analysis of a C1 gene fragment of psittacine beak and feather disease virus amplified by real-time polymerase chain reaction indicates a possible existence of genotypes [1].
• Currently, there is a requirement to develop BFDV antigen for diagnostic purposes and since efforts to propagate BFDV in vitro have so far been unsuccessful the entire coding region of BFDV ORF C1 was expressed in Sf9 insect cells using a baculovirus expression system [2].
• No protein was detected after induction of full-length C1 expression in Escherichia coli [3].
• Porcine circovirus type 2 and beak and feather disease virus show similar capsid structures with flat pentameric morphological units, whereas chicken anemia virus has stikingly different protruding pentagonal trumpet-shaped units [4].
• Furthermore, BFDV propagated in chicken embryo cells was antigenically related to the capsid antigen(s) of the other polyomaviruses [5].

High impact information on C1

• The ability of CP to bind DNA, coupled with the karyophilic nature of this protein, strongly suggests that it may be responsible for nuclear targeting of the viral genome [6].
• The three ORFs were ORF1 that presumably encodes the Rep protein, ORF2 presumably the major capsid protein, and the ORF previously designated ORF5 [7].
• The entire coding region of BFDV ORF C1, the presumptive capsid, was expressed in Sf9 insect cells using baculovirus expression system [2].
• Both new circoviruses shared genome organizational features with previously characterized circoviruses, such that both contained two major, inversely-arranged open reading frames encoding the putative replication-associated and capsid proteins, and both contained a potential stem-loop and nonanucleotide motif [8].
• Interestingly, the complete nucleotide sequence of the viruses and the predicted amino acid sequence of the replication associated protein (ORF1) grouped the viruses similarly, whereas the capsid protein (ORF2) comparisons revealed different relations among the groups, suggesting the possibility of genomic recombination in PCV2 [9].

Biological context of C1

• Open reading frame analysis shows that the genome of all Taiwanese GoCV isolates could encode four proteins: V1 (Rep, 293 amino acids), V2 (37 amino acids), C1 (capsid, 250 amino acids), and C2 (99 amino acids) [10].
• A real-time polymerase chain reaction was developed amplifying a 202 base pair fragment of the region encoding the capsid protein C1 and detecting 100 to 1000 genome equivalents [1].
• Three major immunorelevant epitopes of capsid protein showed variations in amino acid sequences [11].

Anatomical context of C1

• Here we report on the subcellular distribution of the beak and feather disease virus (BFDV) capsid protein (CP) and replication-associated protein (Rep) expressed via recombinant baculoviruses in an insect cell system and test the hypothesis that the CP is responsible for transporting the viral genome, as well as Rep, across the nuclear envelope [6].

Associations of C1 with chemical compounds

• The sizes of V1, C1 and C2 proteins of all Taiwanese isolates and the German GoCV isolates were identical [10].

Analytical, diagnostic and therapeutic context of C1

• The immune sera detected C1 with an apparent molecular weight of 27 kDa in western blots of organ homogenates of BFDV-infected birds [3].
• Epitope mapping of the major capsid protein of type 2 porcine circovirus (PCV2) by using chimeric PCV1 and PCV2 [12].
• Recombinant expression of a truncated capsid protein of beak and feather disease virus and its application in serological tests [3].

References