Biol 254, Fall 2005

The Roles of Cytoskeletal Dynamics in Development
Biol 254 - Seminar in Cell Biology
Fall 2005

Wednesdays 10am
512 Fordham Hall

When it's your turn, please send me two primary research articles that are related (1) to each other, (2) to cytoskeletal dynamics and development, and (3) to the specific topic your week falls under. Please send the papers a week in advance, along with a sentence introducing the papers that I can add to this page. If the papers don't appear online soon after, please check with me to be sure they got to me (since email systems sometimes reject large attachments). Thanks, Bob

Links between microtubules and the actin cytoskeleton

Sept 7: Bob Goldstein
Crazy old papers: these were some of the classic experiments that suggested that there must be some sort of communication between mitotic spindles and the actin cortex.

Pollard, T (2004). Ray Rappaport Chronology: Twenty-Five Years of Seminal Papers on Cytokinesis in the Journal of Experimental Zoology. J Exp Zool 301A:9-14.

Rappaport, R and Rappaport, BN (1988). Reversing Cytoplasmic Flow in Nucleated, Constricted Sand Dollar Eggs. J Exp Zool 247:92-98.

Sept 21: Jeff Molk
These papers deal with remodeling of the actin cytoskeleton by microtubules.

Waterman-Storer C, Duey DY, Weber KL, Keech J, Cheney RE, Salmon ED, Bement WM (2000). Microtubules remodel actomyosin networks in Xenopus egg extracts via two mechanisms of F-actin transport. J Cell Biol. 150:361-76.

Alsop GB, Zhang D (2004). Microtubules are the only structural constituent of the spindle apparatus required for induction of cell cleavage. J Cell Biol. 162:383-90.

Sept 28: Carrie Bacon
These papers deal with APC and IQGAP1, two important links between microtubules and the actin cortex.

Rosin-Arbesfeld R, Ihrke G, Bienz M (2001). Actin-dependent membrane association of the APC tumour suppressor in polarized mammalian epithelial cells. EMBO J. 20:5929-39.

Jun Noritake, Takashi Watanabe, Kazumasa Sato, Shujie Wang, and Kozo Kaibuchi (2005). IQGAP1: a key regulator of adhesion and migration. J. Cell Sci. 118: 2085-2092.

Asymmetric spindle positioning and spindle rotation

Oct 12: Willow Gabriel
Two classic papers on how spindles/nuclei move to specific cortical sites, using non-genetic direct manipulations to cell components.

Lutz D, Hamaguchi Y, Inoue S (1988). Micromanipulation studies of the asymmetric positioning of the maturation spindle in Chaetopterus sp. oocytes: I. Anchorage of the spindle to the cortex and migration of a displaced spindle. Cell Motil Cytoskeleton. 11:83-96.

Hyman AA (1989). Centrosome movement in the early divisions of Caenorhabditis elegans: a cortical site determining centrosome position. J. Cell Biol 109:1185-93.

Oct 19: Minna Roh
These papers look at spindle rotation in Drosophila -- Kaltschmidt's paper looks at this in neuroblasts and Bellaiche's paper looks in sensory organ precursor cells. Both papers utilize live-imaging, which is cool, and Bellaiche's paper also uses a neat way of looking at the SOPs by making holes/windows in the pupal cases and then imaging directly.

Kaltschmidt JA, Davidson CM, Brown NH, Brand AH (2000). Rotation and asymmetry of the mitotic spindle direct asymmetric cell division in the developing central nervous system. Nat Cell Biol. 2(1):7-12.

Bellaiche Y, Gho M, Kaltschmidt JA, Brand AH, Schweisguth F (2001). Frizzled regulates localization of cell-fate determinants and mitotic spindle rotation during asymmetric cell division. Nat Cell Biol. 3(1):50-7.

Oct 26: Erin McCarthy
These papers look at G-protein signaling and spindle positioning. The paper from Gonczy's lab does some cool experiments to show how G-protein signaling regulates pulling forces to position a spindle asymmetrically in the early C. elegans embryo, while the Du and Macara paper gives the first clue as to how G protein signaling might position a spindle, by showing a direct interaction of a G-protein signaling component with a microtubule-associated protein in tissue culture cells.

Colombo K, Grill SW, Kimple RJ,Willard FS, Siderovski DP, Gonczy P (2003) Translation of Polarity Cues into Asymmetric Spindle Positioning in Caenorhabditis elegans Embryos. Science 300:1957-61.

Du Q and Macara IG (2004). Mammalian Pins Is a Conformational Switch that Links NuMA to Heterotrimeric G Proteins. Cell, 119:503–516.

Membrane dynamics and vesicle transport

Nov 2: Dan Marston
These papers investigate how endocytosis of E-cadherin regulates adhesion. The first shows how Hakai (japanese for destruction) ubiquitinates E-cadherin, targetting it for destruction and reducing adhesion downstream of HGF "scatter factor". The second shows how Wnt11 triggers internalisation of E-cadherin during morphogenesis which modulates the adhesive properties of the responding cells.

Fujita Y, Krause G, Scheffner M, Zechner D, Leddy HE, Behrens J, Sommer T, Birchmeier W. (2002). Hakai, a c-Cbl-like protein, ubiquitinates and induces endocytosis of the E-cadherin complex. Nat Cell Biol. 4:222-31.

Ulrich F, Krieg M, Schotz EM, Link V, Castanon I, Schnabel V, Taubenberger A, Mueller D, Puech PH, Heisenberg CP. (2005) Wnt11 functions in gastrulation by controlling cell cohesion through Rab5c and E-cadherin. Dev Cell 9:555-64.

Nov 9: Nate Dudley
Both these papers investigate the molecular mechanisms required for phagocytosis during apoptosis.

Gumienny et al. (2001). CED-12/ELMO, a Novel Member of the CrkII/Dock180/ Rac Pathway, Is Required for Phagocytosis and Cell Migration. Cell 107: 27–41.

deBakker et al. (2004). Phagocytosis of Apoptotic Cells Is Regulated by a UNC-73/TRIO-MIG-2/RhoG Signaling Module and Armadillo Repeats of CED-12/ELMO. Current Biology 14:2208–2216.

Nov 16: Gidi Shemer
This week on “membrane dynamics and the cytoskeleton” we will focus on syncytia and cellularization. In the first paper, Papoulas et al. do a thorough study suggesting that during Drosophila’s embryonic cellularization a dynein-based mechanism allows trafficiking of the golgi to the newly formed cleavage furrows, where it is probably needed for de novo membrane synthesis. In the second paper Maddox et al identify the first Anillins in worms and describe how they act with cytoskeletal elements to mediate membrane dynamics in embryos, as well as in the syncytial gonad. Although critical questions (especially actin-anillin interactions) are yet to be addressed, I find this paper important as it is only one of a few studies that look at what I find to be a fascinating process, the ability of nuclei to be a part of a syncytium and at the same time, behave like independent cells. I strongly encourage you to watch the first paper movies (see below).

Papoulas et al (2005). The golgin Lava lamp mediates dynein-based Golgi movements during Drosophila cellularization. Nature Cell Biology 7:612-618.
Movies

Maddox et al. (2005) Distinct roles for two C. elegans anillins in the gonad and early embryo. Development 132:2837-2848.
Movies

Axon Outgrowth

Nov 30: Jacob Sawyer

Cytoskeleton and Cell Migration Labs at UNC Chapel Hill