Chapter 15: Rhabdoviridae Flashcards
1
Q
virion
A
Usually bullet-like
Helical symmetry
Enveloped
Genome: (-) ssRNA, 11-15kb
2
Q
Hosts
A
Animals
Plants
Many have broad host ranges
3
Q
Rabies
A
wide host range animal reservoir zoonotic transmission entry through broken skin almost always fatal endemic
4
Q
≥ 5 types of proteins
A
Nucleoprotein Phosphoprotein Large protein Matric protein Glycoprotein
5
Q
Nucleoprotein
A
coat RNA -> helical nucleocapsid; 1 N coats 9 nt
6
Q
Phosphoprotein
A
associated with nucleocapsid
7
Q
Large Protein
A
associated with nucleocapsid; large, multi-functional
8
Q
Matrix protein
A
form layer between nucleocapsid and envelope
9
Q
Glycoprotein
A
trimer-> a spike
10
Q
Rhabdovirus genome organization
A
≥ 5 genes -> ≥ 5 structural proteins
11
Q
Attachment
A
- Anti-receptor: G protein (spike)
* Receptor: acetylcholine receptor (AchR: a membrane protein in neuromuscular junctions, responding to neurotransmitter)
12
Q
Entry
A
- Clathrin-mediated endocytosis
- Clathrin: a type of protein on inner surface of cell membrane
- Figure 15.6 top
- Clathrin-coated pit (or region) can force cell membrane to bend around certain foreign particles endocytosis
13
Q
Uncoating
A
- Membrane fusion between envelope and endosome membrane
* Nucleocapsid released into cytoplasm
14
Q
Transcription
A
- In cytoplasm
- L protein as RdRp, active only when complexed with 3 P proteins
- L-P complex moves along (-) RNA from 3’ 5’ end
- L-P complex recognizes a termination signal at each intergenic sequence and at end of L gene
- 5 types of mRNAs and (+) leader RNA (unknown function)
- All 5 mRNAs are capped and polyadenylated
15
Q
L protein has 5 functions
A
o RdRp o Methyl transferase for capping o Guanylyl transferase for capping o Poly A polymerase o Kinase for phosphorylation
