•
（核） or cytoplasm（胞浆）
Protein synthesis is always in the cytoplasm
25
Synthesis
the production of early mRNA & early proteins the replication of genome the production of late mRNA & late proteins
28
3. (-) Single-stranded RNA viruses
Paramyxovirus 副粘病毒
29
4.Retroviruse
nucleus (provirus，前病毒)
(provirus)
HIV,HTLV-l
30
Assembly & Maturation
Nucleus Cytoplasm At membrane
Viral multiplication 病毒增殖
1
Basic Steps of Viral replication Cycle 病毒的复制周期
• • • • • • Adsorption吸附 Penetration穿入 Uncoating脱壳 Biosynthesis生物合成 (eclipse phase隐蔽期) Assembly装配& Release释放
• Need to make genome available
• Once uncoating occurs, enter eclipse phase
22
UNCOATING
• Need to make genome available
• Once uncoating occurs, enter eclipse phase
34
HIV Budding & Maturation
Hsiung, GD et al., Diagnostic Virology 1994 p204 (D. Medina)
35
uninfected
HIV infected
HIV infected (at higher magnifcation)
entry directly across plasma membrane
18
Penetration Naked virus
entry directly across plasma membrane
19
20
UNCOATING
• Need to make genome available
21
UNCOATING
31
Smallpox Virus天花病毒 Assembly & Maturation
F. A. Murphy, School of Veterinary Medicine, University of California, Davis. /fam_ graphics/ downlo ad. html
26
1. ds DNA virus
Cytoplasm`
nsp
nucleus
sp
Herpesviruse 疱疹病毒
27
2. (+) Single-stranded RNA viruses
ribosomes
picornaviruse to serve as a messenger RNA to serve as a template for the synthesis of a complementary (-) strand RNA -- make more (+) RNA strands
• Species（种特异性） • organ specificity（器官特异性）
5
Penetration Enveloped Viruses
• Fusion with cell membrane
• Entry via endosome（经内吞体）
6
Penetration
herpesviruses, paramyxoviruses, HIV
2
ADSORPTION
3
ADSORPTION
• Temperature independent • Requires viral specific binding site • Cellular receptors细胞的受体
4
Significance
The specific attachment determines the host range（属主 范围） of the virus: :
7

Penetration Enveloped Viruses
• Fusion with cell membrane
• Entry via endosome
8
9
10
11
12
13
14
Penetration
Enveloped Viruses
• Fusion with cell membrane • Entry via endosomes, fusion with acidic endosome membrane
15
Penetration
Enveloped Viruses
from Schaechter et al, Mechanisms of Microbial Disease, 3rd ed, 1998
16
Penetration
NON-ENVELOPED VIRUSES
17
Penetration Naked virus
32
Release
Lysis裂解
1
2
Budding through plasma membrane
33
Semliki Forest Virus塞姆利基森林病毒 Budding
Schaechter et al, Mechanisms of Microbial Disease, 3rd ed, 1998
• Eclipse phase lasts until first new virus particle formed
23
24
Synthesis合成 Viral Nucleic Acid & Protein
• Many strategies（多种策略） • Nucleic acid may be made in nucleus