Lab Members

Randy Schekman
schekman@berkeley.edu

A brief biography of Randy is available on the HHMI website.

Kirsten Bacia (post-doc)
bacia@berkeley.edu

I am interested in the molecular requirements and mechanics of membrane morphology changes. Using a combination of biochemistry and light microscopy with giant vesicles as a model system, I try to visualize and further characterize coat-protein-mediated budding in vitro.

Robyn Barfield (post-doc)
rbarfield@berkeley.edu

Fus1p is required at the yeast cell surface for cell fusion to occur during mating. I am trying to determine how three potential coat proteins, Chs5p, Bch1p and Bud7p, help transport Fus1 from a TGN/endosomal compartment to the cell surface.

Ching Jen (Jared) Chen (undergraduate)
chenjared@berkeley.edu

My research focuses on analyzing the mechanisms of internal vesicle formation in Multi-Vesicular Bodies (MVB) through a biochemical approach. The analysis involves the reconstitution of MVB formation in vitro, using different proteases and cytosol with all the components required for MVB formation.

Zhiliang Cheng (post-doc)
zlcheng2007@berkeley.edu

My research is focused on the TGN-to-plasma-membrane transport. Currently,
I am attempting to categorize cargo proteins and identify their
corresponding coat proteins using a selective immunoisolation technique.

Regina Choy (grad student)
regina@berkeley.edu

Abnormal processing of APP that leads to enhanced generation of beta-amyloid peptides is shown to play a central role in the early pathogenesis of Alzheimer's disease. Although APP and gamma-secretase are dynamically sorted through the secretory and endocytic/endosomal pathways, the exact subcellular compartment of beta-amyloid production still remains elusive. The goal of my project is to map the subcellular site(s) of beta-amyloid production using the RNA interference approach, in order to gain better insights into the molecular mechanism of elevated beta-amyloid generation in Alzheimer's disease.

Andrew Davis (grad student)
andrew_davis@berkeley.edu

The peroxisome is a cellular organelle where lipid metabolism and other
oxidative processes occur. Recent studies have shown that the proteins
Pex3p and Pex19p are essential for peroxisome biogenesis. My research aims
to determine what other factors are involved in the formation of
peroxisomes.

Chris Fromme (post-doc)
fromme@berkeley.edu

I am using the in vitro ER-derived vesicle budding assay developed by Jinoh Kim to study several aspects of ER-exit in mammalian cells. Recently, the human developmental disease CLSD (cranio-lenticulo-sutural dysplasia) has been shown to be associated with a missense mutation in one of the two genes coding for the COPII protein Sec23. I have purified recombinant mutant Sec23 and am studying its effects on vesicle morphogenesis in vitro in order to better understand the molecular basis for this disease.

Susan Hamamoto (technician)
susanth@berkeley.edu

Electron microscopy specialist.

Carolyn Haunschild (undergraduate)
chaunschild@berkeley.edu

I'm working on the sequencing of COPII genes to establish the connection
between protein transport and neural tube disease.

Mia Jakobsen (post-doc)
jakobsen@berkeley.edu

The Pma1p proton pump is an essential plasma membrane-localized ATPase required for nutrient uptake and regulation of intracellular pH in yeast. I am using selective immunoisolation to try to identify coat proteins involved in the formation and budding of vesicles containing Pma1p at the trans-Golgi network.

Devon Jensen (grad student)
devjen@berkeley.edu

I work on the in vitro reconstitution of COPII budding in mammalian
cells. In particular, I'm studying the role of different Sec protein
paralogs in the transport of proteins required for planar cell polarity.

Bob Lesch (lab manager)
lesch@berkeley.edu

Martha Morales (lab assistant)

Lelio Orci (collaborator)
lelio.orci@medecine.unige.ch

Kanika Pahuja (née Bajaj) (post-doc)
kanika@berkeley.edu

My research involves exploring the possible existence of large flexible COPII vesicles to accommodate large secretory cargo molecules like chylomicrons and procollagen. More specifically, I am trying to reconstitute the in vitro vesicle budding of Procollagen-I from the ER of mammalian cells.

Mandy Peng (undergraduate)
mpeng@berkeley.edu

I am interested in the trafficking of membrane proteins related to
Alzheimer's Disease. By studying how the recycling of APP back to the cell
surface would affect beta-amyloid peptide production, I hope to gain a
better understanding of the pathology of Alzheimer's disease.

Hemanth Ramesha (undergraduate)
hemanth_ramesha@berkeley.edu

I'm conducting a genetic screen in yeast to identify the protein coat complex important for transport of Chs2p through the late secretory pathway.

Adam Schindler (grad student)
schindla@berkeley.edu

I am studying regulated budding from the ER using the stress-response protein ATF6. During ER stress, ATF6 traffics to the Golgi, where it is protealyzed by Golgi enzymes to release a soluble transcription factor. I have reconstituted stress-regulated ATF6 budding using an in vitro assay. Using this assay, I am exploring the mechanistic details that allow ATF6 to be packaged into a budding vesicle only under certain conditions.

Peggy McCutchan Smith (administrative assistant)
magsmith@berkeley.edu

Trevor Starr (grad student)
t_starr@berkeley.edu

I am interested in sorting signals that mediate intracellular trafficking
and the adaptor proteins that recognize them. My current focus is on the
role of adaptor protein 1 (AP-1) in the intracellular trafficking of
chitin synthase III (Chs3p).

Sean Studer (post-doc)
sean_studer@berkeley.edu

Glycosylation of proteins has been shown to affect protein function. I am attempting to understand how various glycosylation states of proteins involved in COPII formation and budding affect these processes.

John Tran (grad student)
jhtran@berkeley.edu

Multivesicular bodies (MVBs) are endosomes that contain internal vesicles containing protein cargo destined for the vacuole/lysosome, such as proteases and receptors. This has an important consequence for receptor downregulation and retroviral budding. The process of invagination is caused by large multiprotein ESCRT complexes via an unknown mechanism. My goal is to reconstitute this reaction in vitro in order to understand the mechanism behind this important reaction.