Rhoderick Brown is the leader of the Membrane Biochemistry & Molecular Biophysics section at The Hormel Institute. Prof. Brown received his BA degrees in Chemistry and Zoology from the University of North Carolina at Chapel Hill and his PhD degree in Biochemistry from Wake Forest University. He carried out post-doctoral research in the laboratories of Prof. Thomas E. Thompson and Thomas W. Tillack at the University of Virginia.

Education

• Postdoctoral research: Biophysics, University of Virginia, Charlottesville, Virginia
• PhD: Biochemistry, Wake Forest University, Winston Salem, North Carolina
• BA: Chemistry & Zoology, University of North Carolina, Chapel Hill, North Carolina 

Personal interests and hobbies

His outside interests in hiking, canoeing, camping, and cycling began many years ago in western North Carolina.

Professional memberships

• Biophysical Society
• American Society for Biochemistry and Molecular Biology
• Membrane Structure & Assembly Subgroup, Biophysical Society
• Ad hoc NIH Study Section member and consultant
• National Science Foundation reviewer
• Japan Society for Promotion of Science reviewer
• Chemistry & Physics of Lipids Editorial Board
• Journal of Lipids Editorial Board

Research Interests

• Sphingolipid transfer protein structure and function in programmed cell death pathways, inflammation, and cancer
• Cytoplasmic phospholipase A2 structure and function in inflammation and sepsis
• Regulation of amphitropic membrane protein translocation by lipid binding domains
• Sphingolipid roles in raft microdomain formation and stabilization in membranes

Primary Research Areas

Our research focus has centered on proteins that interact transiently with membranes to function. Such proteins include lipid transfer proteins that shuttle sphingolipids between intracellular membranes to help form and maintain “raft” microdomains as well as modular lipid-binding protein domains (e.g. C2-domains) that serve as membrane targeting/anchoring devices that enable bigger proteins to function on membranes.

Our cloning of glyco(sphingo)lipid transfer proteins (GLTPs) from mammals, plants, and fungi enabled X-ray crystallographic resolution of their molecular structures. The unique protein fold (GLTP-fold)  revealed a new protein superfamily.

We have also deciphered how:

• GLTPs accommodate different glycolipids within its glycolipid binding site
• tryptophan functions in glycolipid binding and membrane interaction
• the structural basis for altered glycolipid selectivity by fungal GLTP and the human FAPP2-GLTPH domain

More recently, we discovered new GLTP superfamily members that bind and transfer ceramide-1-phosphate (C1P), i.e. CPTPs.

As published in Nature, we reported structural characterization of human CPTP, its intracellular location in mammalian cells, and showed that CPTP depletion by RNAi leads to C1P over-accumulation in the trans-Golgi. The C1P over-accumulation triggers cytoplasmic phospholipase A2 (cPLA2α) action that releases arachidonic acid used for downstream pro-inflammatory eicosanoid production.

We reported in JBC that including certain phosphoinositides (PIs) to phosphatidylcholine membranes stimulates CPTP activity and mapped the PI interaction site via point mutation analyses to di-arginine residues in the helix 3-4 connecting loop. 

We reported in Autophagy that human CPTP functions to endogenously regulate autophagy and inflammasome assembly that drives interleukin release (IL1B and IL18). In contrast, GLTP overexpression induces necroptotic cell death in certain colon cancer cell types. The findings could ultimately facilitate use of GLTP superfamily proteins as nano-devices to selectively manipulate cellular sphingolipid levels to enable novel programmed cell death-based therapeutic approaches for selectively destroying cancer cells and treating other diseases. 

In eLife, we recently reported insights into the selection mechanism used by cPLA2α C2-domain to target phosphatidyl-choline in membranes for arachidonic acid release. The findings could help develop new treatments for wound-healing, sepsis, and other inflammation-associated pathologic conditions, including cancer.

Awards

• IJ Holton Endowed Professorship, 2018
• Sphingolipid transfer protein research featured in the ‘Lipid News’ section of the March 2014 issue of ASBMB TODAY 

Research Support

• Longstanding support by NIGMS-GM45228 and the Hormel Foundation
• NCI- CA121493
• NHLBI-HL08214
• NHLBI-HL125353 
• Southern Minnesota Paint the Town Pink