figure 9-2 molecular biology of the cell (© garland ...biology.hunter.cuny.edu/cellbio/feinstein...

Figure 9-2 Molecular Biology of the Cell (© Garland Science 2008)

Figure 9-24 Molecular Biology of the Cell (© Garland Science 2008)

Figure Q9-3 Molecular Biology of the Cell (© Garland Science 2008)

Figure 9-14 Molecular Biology of the Cell (© Garland Science 2008)

Figure 9-13 Molecular Biology of the Cell (© Garland Science 2008)

Figure 9-15 Molecular Biology of the Cell (© Garland Science 2008)

Figure 9-18 Molecular Biology of the Cell (© Garland Science 2008)

Figure 9-21 Molecular Biology of the Cell (© Garland Science 2008)

Figure 9-20 Molecular Biology of the Cell (© Garland Science 2008)

Figure 9-22 Molecular Biology of the Cell (© Garland Science 2008)

Figure 9-17 Molecular Biology of the Cell (© Garland Science 2008)

Drugs  can  affect  filament  assembly

A PAR-1–dependent orientation gradient of dynamic microtubules directs posterior cargo transport in the

Drosophila oocyte

Richard M. Parton, Russell S. Hamilton, Graeme Ball, Lei Yang, C. Fiona Cullen, Weiping Lu, Hiroyuki Ohkura, and Ilan Davis

JCB Volume 194(1):121-135

July 11, 2011

© 2011 Parton et al.

A dynamic network of MTs extends throughout the oocyte posterior.

Parton R et al. JCB 2011;194:121-135

© 2011 Parton et al.

EB1 tracks the plus ends of dynamic MTs throughout the oocyte.

Parton R et al. JCB 2011;194:121-135

© 2011 Parton et al.

Staufen protein is transported on MTs at the oocyte posterior.

Parton R et al. JCB 2011;194:121-135

© 2011 Parton et al.

Analysis of EB1 trajectories reveals a graded bias in MT orientation.

Parton R et al. JCB 2011;194:121-135

© 2011 Parton et al.

MT nucleation occurs at discrete foci along the cortex but is absent from the posterior.

Parton R et al. JCB 2011;194:121-135

© 2011 Parton et al.

MTs are nucleated around the entire posterior in par-1 hypomorphic mutant oocytes, abolishing the orientation bias.

Parton R et al. JCB 2011;194:121-135

© 2011 Parton et al.

A biased random organization of MTs in the oocyte delivers cargoes to the posterior.

Parton R et al. JCB 2011;194:121-135

© 2011 Parton et al.

Figure 7-5 Molecular Biology of the Cell (© Garland Science 2008)

Figure 7-92 Molecular Biology of the Cell (© Garland Science 2008)

Figure 7-94 Molecular Biology of the Cell (© Garland Science 2008)

Figure 7-95 Molecular Biology of the Cell (© Garland Science 2008)

Figure 7-96 Molecular Biology of the Cell (© Garland Science 2008)

Figure 7-97 Molecular Biology of the Cell (© Garland Science 2008)

Figure 7-98 Molecular Biology of the Cell (© Garland Science 2008)

Figure 7-106 Molecular Biology of the Cell (© Garland Science 2008)

Figure 7-110 Molecular Biology of the Cell (© Garland Science 2008)

Figure 7-112 Molecular Biology of the Cell (© Garland Science 2008)

The Fate of mRNA Loaded With the miRISC

Targeted mRNA accumulates in P bodies

mRNA is stored in P bodies, undergoes degradation, or reenters the translation pathway

from Rana, Nature Rev.Mol.Cell Biol. 8, 23 (2007)

miRNAs Promote mRNA Deadenylation

from Huntzinger and Izaurralde, Nature Rev.Genet. 12, 99 (2011)

miRNA guide strand associates with AGO

AGO interacts with GW182

GW182 may compete with eIF4G for binding to PABPC and prevents mRNA circularization

Assembly of AGO-GW182-PABPC complex triggers deadenylation by CAF1-CCR4-NOT

GW182 may reduce the affinity of PABPC for the poly(A) tail

Fate of Deadenylated mRNAs

from Huntzinger and Izaurralde, Nature Rev.Genet. 12, 99 (2011)

Deadenylated mRNAs are stored in a translationally repressed state

Deadenylated mRNAs are decapped by DCP2 associated with decapping activators

Decapped mRNA is degraded by XRN1

Overview of RNA-Mediated Gene Silencing

from Eulalio et al., Nature Rev.Mol.Cell Biol. 8, 9 (2007)

siRNA triggers endonucleolytic cleavage of perfectly-matched complementary targets

The resulting mRNA fragments are degraded

miRNA triggers accelerated deadenylation and decapping of partially-complementary targets and requires Argonaute proteins and a P-body component

Cleavage is catalyzed by Argonaute proteins

miRNA represses translation

siRNA

miRNA

A MicroRNA Regulates Neuronal Differentiation by Controlling Alternative Splicing

miR-124 targets a component of a repressor of neuron-specific genes

miR-124 results in reduced expression of PTBP1 leading to the accumulation of PTBP2

PTBP2 results in a global switch to neuron- specific alternative splicing patterns

from Makeyev et al., Mol.Cell 27, 435 (2007)