Christopher J. Westlake, Ph.D.
Christopher J. Westlake, Ph.D.
Investigator
Head, Membrane Trafficking and Signaling Section

Center for Cancer Research
National Cancer Institute

Building 560, Room 22-96C
Frederick, MD 21702-1201
301-846-7594

Dr. Westlake’s laboratory uses advanced fluorescence and electron microscopy imaging techniques, biochemical approaches and zebrafish models to investigate membrane trafficking processes regulated by the Rab small GTPase family that are important in development and disease. His current work focuses on a Rab11-Rab8 cascade which functions in primary cilium formation and apical membrane formation in polarized cells. His lab is also investigating the role of Rabs in the regulation of ciliary Hedgehog signaling. Defects in primary cilium formation and function are important in ciliopathy, diseases linked to primary cilia dysfunction, and cancer.

Areas of Expertise
1) membrane trafficking, 2) Rab GTPases, 3) primary cilia, 4) ciliopathy, 5) superresolution microscopy, 6) Hedgehog signaling

The transmission of cellular signals via membrane transport is important for cell homeostasis, growth, motility, and communication. More than 60 Rabs and their associated effectors and modulators regulate membrane vesicle formation, transport, and fusion. Defects in Rab-dependent trafficking are associated with degenerative and neurological disorders and cancer. 


Rabs are activated to the GTP-bound state by guanine nucleotide exchange factors (GEF), which catalyze GDP release and reloading of GTP, and inactivated by GTPase-activating proteins (GAPs). In the active state, Rabs associate with effector proteins that are important for regulating membrane transport. Interestingly, Rabs have also been shown to bind GEFs and GAPs as effectors and this appears to be important for regulating downstream membrane trafficking steps. The overall focus of Dr. Westlake's research is on understanding the mechanisms that regulate Rab-dependent membrane transport important in signaling and disease.

One focus of the lab is to understand the molecular mechanism of the Rab11-Rab8 cascade important for primary cilium formation, termed ciliogenesis, and apical membrane formation in polarized cells. Rab8 was previously identified as a regulator of ciliogenesis following the discovery that Rabin8, the Rab8 GEF, associates with the BBSome, a core group of Bardet-Biedl syndrome (BBS) proteins. The primary cilium is present on most cells and defects associated with ciliary signaling, including the Sonic hedgehog pathway, have been linked to BBS and a growing list of genetic diseases and certain cancers.

Our prior work suggests that ciliogenesis initiation is preceded by the signaling-dependent binding of Rabin8 to Rab11. Rabin8 is transported via Rab11-recycling endosomes to the centrosome where Rab8 is activated to assemble the primary cilium membrane. We have developed advanced microscopy techniques to monitor in real-time the assembly of the primary cilium - a process completed in approximately 100 minutes.

Cell biology, proteomics, biochemistry and genetics approaches are being used to indentify and characterize associated factors in this pathway. As an example of this approach, mass spectrometry analysis of purified LAP (localization and affinity purification)-tagged Rabin8 was used to identify interactions with the TRAPPII complex, found to be required for Rabin8 centrosomal targeting and ciliogenesis. We are also investigating the roles of these and other membrane transport pathways in the sorting of receptors to the cilia and in the transmission of ciliary signals within the cell.

Scientific Focus Areas:
Biomedical Engineering and Biophysics, Cancer Biology, Cell Biology, Developmental Biology
Selected Key Publications
  1. Lu Q, Insinna C, Ott C, Stauffer J, Pintado PA, Rahajeng J, Baxa U, Walia V, Cuenca A, Hwang YS, Daar IO, Lopes S, Lippincott-Schwartz J, Jackson PK, Caplan S, Westlake CJ
    Nat. Cell Biol.. In press: 2015. [ Journal Article ]
  2. Westlake CJ, Junutula JR, Simon GC, Pilli M, Prekeris R, Scheller RH, Jackson PK, Eldridge AG.
    Proc. Natl. Acad. Sci. U.S.A. 104: 1236-41, 2007. [ Journal Article ]
  3. Westlake CJ, Baye LM, Nachury MV, Wright KJ, Ervin KE, Phu L, Chalouni C, Beck JS, Kirkpatrick DS, Slusarski DC, Sheffield VC, Scheller RH, Jackson PK.
    Proc. Natl. Acad. Sci. U.S.A. 108: 2759-64, 2011. [ Journal Article ]
  4. Asante D, Maccarthy-Morrogh L, Townley AK, Weiss MA, Katayama K, Palmer KJ, Suzuki H, Westlake CJ, Stephens DJ.
    J. Cell. Sci. 126: 5189-97, 2013. [ Journal Article ]
  5. Greer YE, Westlake CJ, Gao B, Bharti K, Shiba Y, Xavier CP, Pazour GJ, Yang Y, Rubin JS.
    Mol. Biol. Cell. 25: 1629-40, 2014. [ Journal Article ]

In 2004, Dr. Westlake obtained his Ph.D. in Biochemistry under the supervision of Dr. Roger Deeley at Queen's University in Canada. While there, he investigated the structure/function and trafficking of multidrug resistance proteins (MRP) that are important in resistance to chemotherapeutics. He then joined Dr. Richard Scheller at Genentech as a postdoctoral fellow investigating membrane trafficking regulation by the Rab small GTPase family. In 2011, Dr. Westlake joined the Laboratory of Cell and Developmental Signaling at the Center for Cancer Research where he studies membrane trafficking pathways important in ciliopathy, diseases linked to primary cilia dysfunction, and cancer.

Name Position
Adrian Cuenca Ph.D. Postdoctoral Fellow (CRTA)
Christine Kettenhofen Ph.D. Postdoctoral Fellow (CRTA)
Quanlong Lu Ph.D. Postdoctoral Fellow (Visiting)
Jimmy Stauffer Ph.D. Research Biologist
Vijay Walia Ph.D. Postdoctoral Fellow (Visiting)

Summary

Dr. Westlake’s laboratory uses advanced fluorescence and electron microscopy imaging techniques, biochemical approaches and zebrafish models to investigate membrane trafficking processes regulated by the Rab small GTPase family that are important in development and disease. His current work focuses on a Rab11-Rab8 cascade which functions in primary cilium formation and apical membrane formation in polarized cells. His lab is also investigating the role of Rabs in the regulation of ciliary Hedgehog signaling. Defects in primary cilium formation and function are important in ciliopathy, diseases linked to primary cilia dysfunction, and cancer.

Areas of Expertise
1) membrane trafficking, 2) Rab GTPases, 3) primary cilia, 4) ciliopathy, 5) superresolution microscopy, 6) Hedgehog signaling

Research

The transmission of cellular signals via membrane transport is important for cell homeostasis, growth, motility, and communication. More than 60 Rabs and their associated effectors and modulators regulate membrane vesicle formation, transport, and fusion. Defects in Rab-dependent trafficking are associated with degenerative and neurological disorders and cancer. 


Rabs are activated to the GTP-bound state by guanine nucleotide exchange factors (GEF), which catalyze GDP release and reloading of GTP, and inactivated by GTPase-activating proteins (GAPs). In the active state, Rabs associate with effector proteins that are important for regulating membrane transport. Interestingly, Rabs have also been shown to bind GEFs and GAPs as effectors and this appears to be important for regulating downstream membrane trafficking steps. The overall focus of Dr. Westlake's research is on understanding the mechanisms that regulate Rab-dependent membrane transport important in signaling and disease.

One focus of the lab is to understand the molecular mechanism of the Rab11-Rab8 cascade important for primary cilium formation, termed ciliogenesis, and apical membrane formation in polarized cells. Rab8 was previously identified as a regulator of ciliogenesis following the discovery that Rabin8, the Rab8 GEF, associates with the BBSome, a core group of Bardet-Biedl syndrome (BBS) proteins. The primary cilium is present on most cells and defects associated with ciliary signaling, including the Sonic hedgehog pathway, have been linked to BBS and a growing list of genetic diseases and certain cancers.

Our prior work suggests that ciliogenesis initiation is preceded by the signaling-dependent binding of Rabin8 to Rab11. Rabin8 is transported via Rab11-recycling endosomes to the centrosome where Rab8 is activated to assemble the primary cilium membrane. We have developed advanced microscopy techniques to monitor in real-time the assembly of the primary cilium - a process completed in approximately 100 minutes.

Cell biology, proteomics, biochemistry and genetics approaches are being used to indentify and characterize associated factors in this pathway. As an example of this approach, mass spectrometry analysis of purified LAP (localization and affinity purification)-tagged Rabin8 was used to identify interactions with the TRAPPII complex, found to be required for Rabin8 centrosomal targeting and ciliogenesis. We are also investigating the roles of these and other membrane transport pathways in the sorting of receptors to the cilia and in the transmission of ciliary signals within the cell.

Scientific Focus Areas:
Biomedical Engineering and Biophysics, Cancer Biology, Cell Biology, Developmental Biology

Publications

Selected Key Publications
  1. Lu Q, Insinna C, Ott C, Stauffer J, Pintado PA, Rahajeng J, Baxa U, Walia V, Cuenca A, Hwang YS, Daar IO, Lopes S, Lippincott-Schwartz J, Jackson PK, Caplan S, Westlake CJ
    Nat. Cell Biol.. In press: 2015. [ Journal Article ]
  2. Westlake CJ, Junutula JR, Simon GC, Pilli M, Prekeris R, Scheller RH, Jackson PK, Eldridge AG.
    Proc. Natl. Acad. Sci. U.S.A. 104: 1236-41, 2007. [ Journal Article ]
  3. Westlake CJ, Baye LM, Nachury MV, Wright KJ, Ervin KE, Phu L, Chalouni C, Beck JS, Kirkpatrick DS, Slusarski DC, Sheffield VC, Scheller RH, Jackson PK.
    Proc. Natl. Acad. Sci. U.S.A. 108: 2759-64, 2011. [ Journal Article ]
  4. Asante D, Maccarthy-Morrogh L, Townley AK, Weiss MA, Katayama K, Palmer KJ, Suzuki H, Westlake CJ, Stephens DJ.
    J. Cell. Sci. 126: 5189-97, 2013. [ Journal Article ]
  5. Greer YE, Westlake CJ, Gao B, Bharti K, Shiba Y, Xavier CP, Pazour GJ, Yang Y, Rubin JS.
    Mol. Biol. Cell. 25: 1629-40, 2014. [ Journal Article ]

Biography

In 2004, Dr. Westlake obtained his Ph.D. in Biochemistry under the supervision of Dr. Roger Deeley at Queen's University in Canada. While there, he investigated the structure/function and trafficking of multidrug resistance proteins (MRP) that are important in resistance to chemotherapeutics. He then joined Dr. Richard Scheller at Genentech as a postdoctoral fellow investigating membrane trafficking regulation by the Rab small GTPase family. In 2011, Dr. Westlake joined the Laboratory of Cell and Developmental Signaling at the Center for Cancer Research where he studies membrane trafficking pathways important in ciliopathy, diseases linked to primary cilia dysfunction, and cancer.

Team

Name Position
Adrian Cuenca Ph.D. Postdoctoral Fellow (CRTA)
Christine Kettenhofen Ph.D. Postdoctoral Fellow (CRTA)
Quanlong Lu Ph.D. Postdoctoral Fellow (Visiting)
Jimmy Stauffer Ph.D. Research Biologist
Vijay Walia Ph.D. Postdoctoral Fellow (Visiting)