4. Figure 18.6 Signal
NUCLEUS
Chromatin
Chromatin modification:
DNA unpacking involving
histone acetylation and
DNA demethylation
DNA
Gene
Gene available
for transcription
RNA Exon
Primary transcript
Transcription
Intron
RNA processing
Cap
Tail
mRNA in nucleus
Transport to cytoplasm
CYTOPLASM
mRNA in cytoplasm
TranslationDegradation
of mRNA
Polypeptide
Protein processing, such
as cleavage and
chemical modification
Active protein
Degradation
of protein
Transport to cellular
destination
Cellular function (such
as enzymatic activity,
structural support)
5. Figure 18.6a
Signal
NUCLEUS
Chromatin
Chromatin modification:
DNA unpacking involving
histone acetylation and
DNA demethylation
DNA
Gene
Gene available
for transcription
RNA Exon
Primary transcript
Transcription
Intron
RNA processing
Cap
Tail
mRNA in nucleus
Transport to cytoplasm
CYTOPLASM
6. Figure 18.6b
CYTOPLASM
mRNA in cytoplasm
TranslationDegradation
of mRNA
Polypeptide
Protein processing, such
as cleavage and
chemical modification
Active protein
Degradation
of protein
Transport to cellular
destination
Cellular function (such
as enzymatic activity,
structural support)
22. Control combinatorial de la activación génica
• Una combinación particular de elementos de
control puede activar la transcripción sólo cuando
las proteínas activadoras apropiadas están
presentes.
23. Figure 18.11
Control
elements
Enhancer Promoter
Albumin gene
Crystallin
gene
LIVER CELL
NUCLEUS
Available
activators
Albumin gene
expressed
Crystallin gene
not expressed
(a) Liver cell
LENS CELL
NUCLEUS
Available
activators
Albumin gene
not expressed
Crystallin gene
expressed
(b) Lens cell
37. Figure 18.14
Protein to
be degraded
Ubiquitin
Ubiquitinated
protein
Proteasome
Protein entering
a proteasome
Proteasome
and ubiquitin
to be recycled
Protein
fragments
(peptides)
La ubiquitina es una pequeña proteína reguladora que ha sido
encontrada en la mayoría de los tejidos de los organismos
eucariotas. Una de sus muchas funciones es dirigir el reciclaje de
proteínas (wikipedia 2013).
40. (a) Primary miRNA transcript
Hairpin
miRNA
miRNA
Hydrogen
bond
Dicer
miRNA-
protein
complex
mRNA degraded Translation blocked
(b) Generation and function of miRNAs
5ʹ′ 3ʹ′
Figure 18.15
Hairpin=Horquillas son un
tipo común de estructura
secundaria en moléculas
de ARN.
http://www.nature.com/scitable/definition/hairpin-
loop-mrna-314