For our Journal Club on April 29, Sun Hae Hong presented the following paper:
The molecular basis for the endocytosis of small R-SNAREs by the clathrin adaptor CALM. Miller SE, Sahlender DA, Graham SC, Höning S, Robinson MS, Peden AA, Owen DJ. Cell. 2011 Nov 23;147(5):1118-31. PMID: 22118466
Schematic representation of the model of VAMP8 trafficking from the plasma membrane.
For our new Microtubules and Mitosis Journal Club on April 25, members of the Drubin/Barnes Lab, Eva Nogales Lab, and Ahmet Yildiz Lab discussed the following paper, selected by Nate Krefman:
Estimating the microtubule GTP cap size in vivo. Seetapun D, Castle BT, McIntyre AJ, Tran PT, Odde DJ. Curr Biol. 2012 Sep 25;22(18):1681-7. PMID: 22902755
Example EB1 comet from an EB1-EGFP LLCPK1 cell and the corresponding fluorescence intensity (FI) linescan, blue line.
For our Journal Club on April 18, Akemi Kunibe presented the following paper:
Endoplasmic reticulum-associated mitochondria-cortex tether functions in the distribution and inheritance of mitochondria. Lackner LL, Ping H, Graef M, Murley A, Nunnari J. Proc Natl Acad Sci U S A. 2013 Feb 5;110(6):E458-67. PMID: 23341591.
The ER is a component of the Num1 mitochondria–cell cortex tether.
For our Journal Club on February 7, Yansong Miao will present the following paper:
Rocket launcher mechanism of collaborative actin assembly defined by single-molecule imaging. Breitsprecher D, Jaiswal R, Bombardier JP, Gould CJ, Gelles J, Goode BL. Science. 2012 Jun 1;336(6085):1164-8. doi: 10.1126/science.1218062. PMID: 22654058
Proposed ‘rocket launcher’ model for mDia1-APC collaboration during actin filament assembly
We now present to you a brand new theme song to introduce the world to all of the awesome people in the Drubin/Barnes Lab!
The Drubin-Barnes Lab!
(Parody of The Brady Bunch Theme Song)
Submission for UC-Berkeley MCB Follies 2012-2013
(UC-Berkeley, Dept. of Molecular and Cell Biology)
LYRICS, VOCALS, CAMERA, EDITING: Nathaniel Krefman
ADDITIONAL VOCALS: Akemi Kunibe
STARRING: The Drubin/Barnes Lab at UC-Berkeley (Fall 2012)!
PIs: Profs. David Drubin and Georjana Barnes
1st GROUP (microtubules, spindles, kinetochores, & mitosis in budding yeast): Adrianne Pigula (top left), Nathaniel Krefman (center left), Itziar Ibarlucea-Benitez (bottom left), Prof. Georjana Barnes (center), Anthony Cormier (center right)
2nd GROUP (actin cytoskeleton and endocytosis in mammalian cells and budding yeast): Aaron Cheng (top left square, left), Jasper Weinberg (top left square, right), Rebecca Lu (center left square, left), Lillie Cohn (center left square, center), Akemi Kunibe (center left square, right), Yansong Miao (bottom left square), Prof. David Drubin (center square), Sun Hae Hong (top right square, left), Yidi Sun (top right square, right), Alex Grassart (center right square, left), Daphne Dambournet (center right square, right), Christa Cortesio (bottom right square, left), Eric Lewellyn (bottom right square, right).
________________________________________________
LYRICS:
Here’s the story of a lovely lady.
Who studied what a microtubule’s for.
All her group loves mitosis, like Georjana,
And kinetochores.
Here’s the story of a PI named David,
Who was interested in actin in live cells,
And his group mapped endocytosis dynamics,
Yet they were by themselves.
After their post-docs, where the lady met this fellow,
And named a protein complex DAM instead of DARN,
They knew their groups must form one laboratory.
That’s the way our lab became the Drubin/Barnes!
The Drubin/Barnes!
That’s the way our lab became the Drubin/Barnes!
For our next Journal Club, our summer undergraduate researcher Josh Johnson will present the following paper:
Aurora B dynamics at centromeres create a diffusion-based phosphorylation gradient. Wang E, Ballister ER, Lampson MA. J Cell Biol. 2011 Aug 22;194(4):539-49. PMID: 21844210.
Centromeres (CB-mCherry) and chromosomes (YFP emission) for a single time point. (bottom) Color-coded YFP/CFP emission ratio at different time points. The timestamp (minutes and seconds) is relative to ZM washout at t = 0. Bar, 5 µm.
For our next Journal Club, Adrianne Pigula will present the following paper:
A link between mitotic entry and membrane growth suggests a novel model for cell size control. Anastasia SD, Nguyen DL, Thai V, Meloy M, MacDonough T, Kellogg DR. J Cell Biol. 2012 Apr 2;197(1):89-104. Epub 2012 Mar 26. PMID: 22451696.
A model for signals that link mitotic entry to membrane growth.
For Journal Club on Monday, June 25, Connie Peng presented the following paper:
Functional Repurposing Revealed by Comparing S. pombe and S. cerevisiae Genetic Interactions. Frost A, Elgort MG, Brandman O, Ives C, Collins SR, Miller-Vedam L, Weibezahn J, Hein MY, Poser I, Mann M, Hyman AA, Weissman JS. Cell. 2012 Jun 8;149(6):1339-52. PMID: 22682253.
Scatter plot of correlation coefficients comparing GI profiles for Sp versus Sc. Highlighted examples of pairwise relationships that are correlated in Sp but not Sc are listed below the scatter plot. Bold indicates functional relationships explored in this study. See Table S1 for additional examples of correlated pairwise relationships conserved between Sp and Sc (green), and pairwise relationships that are correlated in Sc but not Sp (cyan) or Sp but not Sc (red).
For our next Journal Club, Yansong Miao will present the following paper:
An actin-dependent mechanism for long-range vesicle transport. Schuh M. Nat Cell Biol. 2011 Oct 9;13(12):1431-6. PMID: 21983562.
Mechanism of directional vesicle transport
Yidi Sun‘s new paper is out now as an electronic publication ahead of print in the journal Molecular Biology of the Cell. Congratulations to Yidi on her great work! The abstract is below. The PDF can be downloaded from MBoC here.
Orm protein phosphoregulation mediates transient sphingolipid biosynthesis response to heat stress via the Pkh-Ypk and Cdc55-PP2A pathways. Sun Y, Miao Y, Yamane Y, Zhang C, Shokat KM, Takematsu H, Kozutsumi Y, Drubin DG. Mol Biol Cell. 2012 Apr 25. PMID: 22535525.
Abstract
Sphingoid intermediates accumulate in response to a variety of stresses, including heat, and trigger cellular responses. However, the mechanism by which stress affects sphingolipid biosynthesis has yet to be identified. Recent studies in yeast suggested that sphingolipid biosynthesis is regulated through phosphorylation of the Orm proteins, which in humans are potential risk factors for childhood asthma. Here, we demonstrate that Orm phosphorylation status is highly responsive to sphingoid bases. We also demonstrate by monitoring temporal changes in Orm phosphorylation and sphingoid base production in cells inhibited for Ypk1 protein kinase activity, that Ypk1 transmits heat stress signals to the sphingolipid biosynthesis pathway via Orm phosphorylation. Our data indicate that heat-induced sphingolipid biosynthesis in turn triggers Orm protein dephosphorylation, making the induction transient. We identified Cdc55-PP2A (protein phosphatase 2A) as a key phosphatase that counteracts Ypk1 activity in Orm mediated sphingolipid biosynthesis regulation. In total, our study reveals a mechanism through which the conserved Pkh-Ypk kinase cascade and Cdc55-PP2A facilitate rapid, transient sphingolipid production in response to heat stress through Orm protein phosphoregulation. We propose that this mechanism serves as the basis for how Orm phosphoregulation controls sphingolipid biosynthesis in response to stress in a kinetically coupled manner.
A feedback regulation pathway in which Orm protein phosphorylation dynamics rapidly and precisely regulate sphingolipid biosynthesis in response to heat stress. See the text for a description.