Biomedical Engineering Reference
In-Depth Information
RNase III domains of Dicer undergo intra-molecular dimerization to form a
single cleavage center and cleave the pre-miRNA separated by 2 nt roughly
about 22 nt away from the termini, simultaneously generating a 3
0
2-nt over-
hang (Zhang et al., 2004). After Dicer activity, the mature miRNA intermediate
has a 2-nt 3
0
overhang on either end of the double-stranded duplex (correspond-
ing to the stem of the pre-miRNA) (Bernstein et al., 2001) (Fig. 1).
NUCLEUS
CYTOPLASM
miRNA Gene
Transcription
(Pri-miRNA)
(A)
n
cap
(Mirtron)
DGCR8
Drosha
Exportin 5
Microprocessor
Complex
Export
TRBP
cap
(A)
n
Maturation
Dicer
Splicing
Pre-miRNA
3'
3'
5'
5'
Unstable Base-pair end
Stable Base-pair end
eIF4E
Strand Selection
miRNP assembly
AGO2
etc.
(A)
n
cap
AND/OR
Translation Initiation
RISC
OR
(A)
n
cap
Translation Elongation
(A)
n
cap
AAAAAA
cap
Deadenylation
P-Body/Stress Granule
