细胞科学
Cell Science
（ 10.4）
蔡国平
10.4 Inter m ediat e fil a m ent
1,T he m olecule structur e of IF
1) 10n m f ila m ent showing a si m ilar spa tial patter n as
M T,to which they m ay be connected.
2) T o today,IF have onl y been identified with
certainl y in anim al cells (?, Plant cells)
3) T he m odel f or IF as se m bly and archit ecture:
M ono m er (a pair of globul ar ter m in al do m ains,a
long ? -h elical regi on.
Di m er (h o m odi m er or hetero dim er),in parall el,ends
aligned
T etr a m er,in antipar allel,bas ic s ubunit, L acking
polar ity
IF s tr uctur e,being com po se d of s tagger ed subunits,
Highly resistant to tensile and m or e resist ant to
che m ical di sruptio n.
4) IF a ss ociat ed p r ot ein
Fi laggr im ( br idg e)
Pl akogl obi n ( f or m e m br ane bi ndi ng spot )
Des m opl akin ( f or des m oso m e)
2,I F asse m bly and disas se m bly
More dif f icult to solubil ize,can b e solubil ized in har sh
ioni c deter gents such SDS,
But Once dis solved,I F can be depol y m eri zed and
r epoly m eri zed r epeatly in vitr o.
I n vivo,I F behave d y na m ically, T her e a pool of I F
subunit s in cells.
I ncor por ation exper im ents,I nto the f ila m ent's inter ior,
I F d y na m ic quali ty can be see n in so m e c ells as th ey
enter and exit m itosi s,by
r epoly m eri zation or r eor ganizati on
the contr ol of dy nam ic equil ibr iu m by phosphor y latio n
and depho sphor y latio n of the I F subunit s,f or exa m ple,
phosphor y latio n of vim entin f ila m ent s by pr otein kinase
A leads to thei r co m plet e disa ss e m bly,
3,T y pes of IF and Fun ction
1) Six t y pes and m ore than 50 gene s and tis s ue-
s pecif ic
T y p e I Ke r at i n e p i t h e l i a
T y p e II Ke r a t i n e p i t h e l i a
T y p e II I V i m e n t i n,m e se n c h y m a l c e l l s
D e sm i n m u sc l e
Gl i al f i b r i l l ar y ac i d i c p r ot e i n ( GF A P ) Gl i al c e l l s,astr oc yt e s
P e r i p h e r i n p e r i p h e r al n e u r on s
T y p e IV N e u r of i l am e n t p r ot e i n s,NF - L N F - M N F - H N e u r on s of c e n t r al an d
P e r i p h e r al n e r v e s
T y p e V L am i n p r ot e i n s A,B,C all c e l l s
T y p e V I N e st i n n e u r on al s t e m c e l l s
中间纤维分类与分布
4,Fu nc tio ns o f IF
B e s i d e s p r o v i d i n g m e c h a n i c a l s t a b i l i t y t o c e l l s
(co nn e c tin g to de sm o s o m e a nd hem ides m os o m e ),IF
c a rry ou t s pe c ia liz e d,tis s ue -s p e c of ic f un c tio n s, B ut
be ing no t inv olv e d in ba s ic un ive rs a l c e ll pro c e sse s s uc h
a s m ito s is a nd c y tok ine s is,
I F - r e l a t e d D i s e a s e s
Cell Science
（ 10.4）
蔡国平
10.4 Inter m ediat e fil a m ent
1,T he m olecule structur e of IF
1) 10n m f ila m ent showing a si m ilar spa tial patter n as
M T,to which they m ay be connected.
2) T o today,IF have onl y been identified with
certainl y in anim al cells (?, Plant cells)
3) T he m odel f or IF as se m bly and archit ecture:
M ono m er (a pair of globul ar ter m in al do m ains,a
long ? -h elical regi on.
Di m er (h o m odi m er or hetero dim er),in parall el,ends
aligned
T etr a m er,in antipar allel,bas ic s ubunit, L acking
polar ity
IF s tr uctur e,being com po se d of s tagger ed subunits,
Highly resistant to tensile and m or e resist ant to
che m ical di sruptio n.
4) IF a ss ociat ed p r ot ein
Fi laggr im ( br idg e)
Pl akogl obi n ( f or m e m br ane bi ndi ng spot )
Des m opl akin ( f or des m oso m e)
2,I F asse m bly and disas se m bly
More dif f icult to solubil ize,can b e solubil ized in har sh
ioni c deter gents such SDS,
But Once dis solved,I F can be depol y m eri zed and
r epoly m eri zed r epeatly in vitr o.
I n vivo,I F behave d y na m ically, T her e a pool of I F
subunit s in cells.
I ncor por ation exper im ents,I nto the f ila m ent's inter ior,
I F d y na m ic quali ty can be see n in so m e c ells as th ey
enter and exit m itosi s,by
r epoly m eri zation or r eor ganizati on
the contr ol of dy nam ic equil ibr iu m by phosphor y latio n
and depho sphor y latio n of the I F subunit s,f or exa m ple,
phosphor y latio n of vim entin f ila m ent s by pr otein kinase
A leads to thei r co m plet e disa ss e m bly,
3,T y pes of IF and Fun ction
1) Six t y pes and m ore than 50 gene s and tis s ue-
s pecif ic
T y p e I Ke r at i n e p i t h e l i a
T y p e II Ke r a t i n e p i t h e l i a
T y p e II I V i m e n t i n,m e se n c h y m a l c e l l s
D e sm i n m u sc l e
Gl i al f i b r i l l ar y ac i d i c p r ot e i n ( GF A P ) Gl i al c e l l s,astr oc yt e s
P e r i p h e r i n p e r i p h e r al n e u r on s
T y p e IV N e u r of i l am e n t p r ot e i n s,NF - L N F - M N F - H N e u r on s of c e n t r al an d
P e r i p h e r al n e r v e s
T y p e V L am i n p r ot e i n s A,B,C all c e l l s
T y p e V I N e st i n n e u r on al s t e m c e l l s
中间纤维分类与分布
4,Fu nc tio ns o f IF
B e s i d e s p r o v i d i n g m e c h a n i c a l s t a b i l i t y t o c e l l s
(co nn e c tin g to de sm o s o m e a nd hem ides m os o m e ),IF
c a rry ou t s pe c ia liz e d,tis s ue -s p e c of ic f un c tio n s, B ut
be ing no t inv olv e d in ba s ic un ive rs a l c e ll pro c e sse s s uc h
a s m ito s is a nd c y tok ine s is,
I F - r e l a t e d D i s e a s e s
