Welcome to the Bolla Lab

We aim to uncover the common principles that govern double membrane biogenesis and transport in Gram-negative bacteria and chloroplasts, and the ways in which these systems have diverged.

Biological membranes, composed largely of lipids and proteins, allow cells to maintain internal conditions distinct from those of the external environment. In eukaryotes, membranes further enable compartmentalisation and functional specialisation within organelles. Most organelles are enclosed by a single membrane, whereas endosymbiotic organelles, such as mitochondria and chloroplasts, derived from Gram-negative bacteria, retain a double envelope with an outer membrane enriched in β-barrel proteins. This additional barrier increases regulatory complexity and requires coordinated transport and quality control across the envelope while preserving membrane integrity.

Our research examines how lipid and protein components are transported across and assembled into the double-envelope membranes of Gram-negative bacteria and chloroplasts. Studying these systems in parallel enables us to distinguish deeply conserved principles from features that have diverged since endosymbiosis.

We combine structural mass spectrometry techniques, including native mass spectrometry and hydrogen–deuterium exchange mass spectrometry, with cryo-electron microscopy to resolve envelope machineries in defined functional states and map their dynamics. Much of our work centres on Pseudomonas pathogens, including Pseudomonas aeruginosa and Pseudomonas syringae, alongside the chloroplast envelope from model organisms. We are particularly interested in lipid transport and outer-membrane homeostasis, β-barrel protein assembly, and protein import across envelopes. Together, these studies provide a mechanistic basis for understanding envelope function in bacterial pathogenicity and antibiotic resistance, and for exploring how chloroplast envelopes support organelle function and stress resilience.

Google scholar:
https://scholar.google.com/citations?user=qkQ5nRQAAAAJ&hl=en

Jani Bolla
Supervisor
Associate Prof Jani Bolla
Louise Johnson Associate Professor of Molecular and Cellular Biochemistry
Contact: jani.bolla@bioch.ox.ac.uk

Jani and his research group use state-of-the-art structural tools such as native mass spectrometry, cryo-electron microscopy and X-ray crystallography to elucidate the molecular mechanisms of large protein machineries involved in transport across biological membranes. Jani studied chemical sciences at Pondicherry University, India and moved to Iowa State University for his doctoral studies. He then worked in Prof. Dame Carol Robinson’s group at the University of Oxford as a postdoctoral research associate. He was awarded a Royal Society University Research Fellowship in 2021 to set up his own research group.

Linda Zheng
PhD student
New College, University of Oxford
Contact: tong.zheng@new.ox.ac.uk
(Sep 2024 – Present)

Linda is a second-year PhD student in the group, jointly supervised by Jani Bolla and Elena Baena-González. Her work focuses on plant stress signalling and sensing at a molecular level. In particular, she is investigating how various metabolic sugars, for example trehalose-6-phosphate, regulate the Sucrose non-fermenting 1-related protein kinase 1 (SnRK1), a central regulator of energy homeostasis. In her free time, she enjoys cooking, going to the gym and running occasionally.

Dushan Zivkovic
Postdoctoral Research Associate
Contact: dushan.zivkovic@bioch.ox.ac.uk
(Feb 2024- Present)

Dušan completed his PhD at Université Paul Sabatier in Toulouse, France, where he studied proteasome complexes specific to developing germ cells. He then spent two years investigating the role of the proteasome in the genesis of idiopathic lung fibrosis.
His current research has two axes: Rubisco isoform diversity in crop and model plants, and quality control mechanisms of chloroplast protein import via the proteasomal pathway (HAPPY-QC). He specialises in proteomics and structural mass spectrometry techniques. His research interests are proteasome biology and methods in structural mass spectrometry.

Rhianon Durant
PhD Student
Pembroke College, University of Oxford
(Oct 2024 - Present)
Contact: rhiannon.durant@pmb.ox.ac.uk

Rhianon DPhil project focuses on utilising structural biology techniques to explore the identity, composition and function of membrane transport complexes in the chloroplast outer envelope membrane. These complexes are essential for chloroplast function and photosynthesis. Therefore, elucidating their structure and mechanisms will likely have implications for future optimisation of crop productivity.

Charlotte Guffick
Postdoctoral Research Associate
Contact: charlotte.guffick@bioch.ox.ac.uk
(Jan 2026 - Present)

Charlotte is a postdoctoral researcher in structural mass spectrometry of membrane proteins. She obtained an MBiochem from the University of York (2017), following which she worked within the Biometrology Unit at the National Physical Laboratory (NPL). In 2023 she earned her PhD in Pharmacology at the University of Cambridge with Prof. Hendrik Van Veen, where her research focused on functional studies of bacterial multidrug efflux pumps and lipid transporters. From 2023-2026 she worked as a postdoctoral researcher at the university of Manchester within the Politis Group, applying her extensive knowledge of membrane protein biochemistry to Hydrogen-Deuterium Exchange Mass Spectrometry studies and method development, focusing on transporter dynamics within native and native-like environments. She joined the Bolla lab in 2026 where her research focuses on utilising structural mass spectrometry approaches to study components of outer membrane biosynthesis in Gram negative bacteria.

Agrima Deedwania
PhD Student
Wolfson College
Contact: agrima.deedwania@wolfson.ox.ac.uk
(Jan 2025 - Present)

Agrima received a B.Tech in Biochemical Engineering and Biotechnology from the Indian Institute of Technology, Delhi. After undergrad, she worked as a research scientist in a MedTech startup: Inito. She is currently pursuing a DPhil on the Interdisciplinary Biosciences DTP co supervised with Harrison steel, focusing on mother machine microfluidics, protein engineering and antimicrobial resistance. Agrima enjoys playing badminton, cycling, hiking and taking pictures of sky in her free time.

Chitra Joshi
Postdoctoral Research Associate
(Jan 2026 - Present)
Contact: chitra.joshi@bioch.ox.ac.uk

Chitra joined the group in 2026 as a postdoctoral research associate exploring the structural basis of protein import via β-barrel protein assemblies in the chloroplast membranes. She specializes in membrane protein biochemistry and structural biology through cryo-electron microscopy. Previously, she gained postdoctoral experience with Professor Simon Newstead where her research focussed on understanding structure and function of prostaglandin (SLCO2A1) and folate (SLC46A1) transporters in humans. She was awarded prestigious Commonwealth Doctoral Scholarship to complete her PhD (Life Sciences) from University of Warwick, UK in the lab of Professor Richard Napier and Professor Alex Cameron researching the structure of plant auxin transporter AUX1. ORCID

Sandy Kaur
Postdoctoral Research Associate
(Oct 2025 - Present)
Contact: sandy.kaur@bioch.ox.ac.uk

Sandy is a structural and computational biologist with experience spanning cryo-electron microscopy (cryo-EM) and tomography (cryo-ET), bioinformatics and algorithm development. After completing a PhD from Dr Mike Strauss and Dr Javier Vargas's lab at McGill University, Montreal, where she was trained to develop image processing algorithms for cryo-EM, Satinder joined the laboratory of Dr Peijun Zhang as a Postdoctoral Research Associate at Diamond Light Source, contributing to groundbreaking studies on bacterial chemotaxis. She later joined Imperial College London as a Research Associate in Bioinformatics at, applying computational innovation to address key biological questions in FPIES. She is currently working with Dr Jani Bolla's lab at the University of Oxford, focusing on developing cryo-EM methods and exploring the molecular structure of the chloroplast beta-barrel assembly machinery.

Yi Wang
PhD Student
Contact: yi.wang@chch.ox.ac.uk
(Jan 2023 - Present)

My research focuses on elucidating the molecular mechanisms of the Dlt proteins and reconstituting the entire D-alanylation pathway in vitro, with an emphasis on characterising the full set of p-p interactions. This work aims to uncover the mechanistic basis of a key cell surface modification in Gram-positive bacteria. Outside the lab, I have a strong interest in humanistic photography.

Aron Czako
PhD Student
St. Catherine’ College
(Oct 2024- Present)
Contact: aron.czako@stcatz.ox.ac.uk