citoesqueleto matriz excl 429

The Cytoskeleton

Figure 3.5

Figure 3.1

The Diversity of Cells

MreBactin like

FtsZtubulin like

Crescentinintermediate filament like

FtsZtubulin likein mitochondriaschloroplasts

Fig. 4-22b, p. 98

(b) Fluorescent LM showing microtubules in green. Amicrotubule-organizing center (pink dot) is visible besideor over most of the cell nuclei (blue).

50 μm

MT axonémicos MT citoplásmicos

Acetilaciones de las tubulinas estabilizan los MT

ColchicineNocadozole

Vinblastine Vincristine

TaxolPaclitaxel

Centrioles

Centrioles

Fig. 4-24b, p. 99

(b) Note the 9 x 3 arrangement of microtubules.The centriole on the right has been cut transversely.

Centrioles and Cilia

Figure 3.6

+ -

Tau en las neuritas y axones

Neurofibrillary tangles(tauopathies)

Centrioles and Cilia

Figure 3.6

Cilia

Fig. 4-26b, p. 101

(b) Many bundles of microfilaments (green) are evident in thisfluorescent LM of fibroblasts, cells found in connective tissue.

100 μm

Microfilaments

Citochalasin

Phaloidin

Fiber Shortening• As sarcomeres shorten, muscle pulls together,

producing tension

Figure 10–13

Skeletal Muscle Innervation

Figure 10–10a, b (Navigator)

Figure 10–3

A Thick Filament

Figure 10–7c

Figure 10–11

Intermediate Filaments

Cytokeratin

Vimentin (mesenchymal)

NF-H-pind (green) and Glial Fibrillary Acidic Protein (GFAP) (red)

Progeria

Cell Junctions• Anchoring junctions

– Hemidesmosomes- between cells in sheets of tissue – Desmosomes- spot-weld animal cells together

• Adhering junctions- cement cells together formed by cadherins

Superfamilia de immunoglobulinas

N-CAM y L1-CAMRetardación y defectos en cuerpo calloso

Células cancerosas bajan las cantidades de cadherinas.

Desmosomes

Cell recognition

Fibroblasts

Tight Junctions

Attachment to Basal Lamina• Hemidesmosomes

Figure 4–2e

Extracellular Matrix

ECM• Extracellular matrix (ECM)

– Surrounds many animal cell– Carbohydrates and protein

• Fibronectins – glycoproteins of ECM– bind to integrins

• Integrins– receptor proteins in plasma membrane

Proteoglycans Cartilage