Identification of a novel intronic variant of ATP6V0A2 in a Han-Chinese family with cutis laxa.

BACKGROUND: Cutis laxa is a connective tissue disease caused by abnormal synthesis or secretion of skin elastic fibers, leading to skin flabby and saggy in various body parts. It can be divided into congenital cutis laxa and acquired cutis laxa, and inherited cutis laxa syndromes is more common in clinic. METHODS: In this study, we reported a case of a Han-Chinese male newborn with ATP6V0A2 gene variant leading to cutis laxa. The proband was identified by whole-exome sequencing to determine the novel variant, and their parents were verified by Sanger sequencing. Bioinformatics analysis and minigene assay were used to verify the effect of this variant on splicing function. RESULTS: The main manifestations of the proband are skin laxity, abnormal facial features, and enlargement of the anterior fontanelle. Whole-exome sequencing showed that the newborn carried a non-canonical splicing-site variant c.117 + 5G > T, p. (?) in ATP6V0A2 gene. Sanger sequencing showed that both parents of the proband carried the heterozygous variant. The results of bioinformatics analysis and minigene assay displayed that the variant site affected the splicing function of pre-mRNA of the ATP6V0A2 gene. CONCLUSIONS: In this study, it was identified that ATP6V0A2 gene c. 117 + 5G > T may be the cause of the disease. The non-canonical splicing variants of ATP6V0A2 gene were rarely reported in the past, and this variant expanded the variants spectrum of the gene. The functional study of minigene assay plays a certain role in improving the level of evidence for the pathogenicity of splicing variants, which lays a foundation for prenatal counseling and follow-up gene therapy.

Structural analysis of ATP bound to the F1-ATPase ß-subunit monomer by solid-state NMR- insight into the hydrolysis mechanism in F1.

ATP-hydrolysis-associated conformational change of the ß-subunit during the rotation of F1-ATPase (F1) has been discussed using cryo-electron microscopy (cryo-EM). Since it is worthwhile to further investigate the conformation of ATP at the catalytic subunit through an alternative approach, the structure of ATP bound to the F1ß-subunit monomer (ß) was analyzed by solid-state NMR. The adenosine conformation of ATP-ß was similar to that of ATP analog in F1 crystal structures. 31P chemical shift analysis showed that the Pα and Pß conformations of ATP-ß are gauche-trans and trans-trans, respectively. The triphosphate chain is more extended in ATP-ß than in ATP analog in F1 crystals. This appears to be in the state just before ATP hydrolysis. Furthermore, the ATP-ß conformation is known to be more closed than the closed form in F1 crystal structures. In view of the cryo-EM results, ATP-ß would be a model of the most closed ß-subunit with ATP ready for hydrolysis in the hydrolysis stroke of the F1 rotation.

FliH and FliI help FlhA bring strict order to flagellar protein export in Salmonella.

The flagellar type III secretion system (fT3SS) switches substrate specificity from rod-hook-type to filament-type upon hook completion, terminating hook assembly and initiating filament assembly. The C-terminal cytoplasmic domain of FlhA (FlhAC) forms a homo-nonameric ring and is directly involved in substrate recognition, allowing the fT3SS to coordinate flagellar protein export with assembly. The highly conserved GYXLI motif (residues 368-372) of FlhAC induces dynamic domain motions of FlhAC required for efficient and robust flagellar protein export by the fT3SS, but it remains unknown whether this motif is also important for ordered protein export by the fT3SS. Here we analyzed two GYXLI mutants, flhA(GAAAA) and flhA(GGGGG), and provide evidence suggesting that the GYXLI motif in FlhAC requires the flagellar ATPase complex not only to efficiently remodel the FlhAC ring structure for the substrate specificity switching but also to correct substrate recognition errors that occur during flagellar assembly.

Single-Cell RNA Sequencing Profiling Cellular Heterogeneity and Specific Responses of Fish Gills to Microplastics and Nanoplastics.

Fish gills are highly sensitive organs for microplastic (MP) and nanoplastic (NP) invasions, but the cellular heterogeneity of fish gills to MPs and NPs remains largely unknown. We employed single-cell RNA sequencing to investigate the responses of individual cell populations in tilapia Oreochromis niloticus gills to MP and NP exposure at an environmentally relevant concentration. Based on the detected differentially expressed gene (DEG) numbers, the most affected immune cells by MP exposure were macrophages, while the stimulus of NPs primarily targeted T cells. In response to MPs and NPs, H+-ATPase-rich cells exhibited distinct changes as compared with Na+/K+-ATPase-rich cells and pavement cells. Fibroblasts were identified as a potential sensitive cell-type biomarker for MP interaction with O. niloticus gills, as evidenced by the largely reduced cell counts and the mostly detected DEGs among the 12 identified cell populations. The most MP-sensitive fibroblast subpopulation in O. niloticus gills was lipofibroblasts. Cell-cell communications between fibroblasts and H+-ATPase-rich cells, neurons, macrophages, neuroepithelial cells, and Na+/K+-ATPase-rich cells in O. niloticus gills were significantly inhibited by MP exposure. Collectively, our study demonstrated the cellular heterogeneity of O. niloticus gills to MPs and NPs and provided sensitive markers for their toxicological mechanisms at single-cell resolution.

pH change accompanying long-distance electrical signal controls systemic jasmonate biosynthesis.

Local damaging stimuli cause a rapid increase in the content of the defense phytohormone jasmonic acid (JA) and its biologically active derivative jasmonoyl-L-isoleucine (JA-Ile) in undamaged distal tissues. The increase in JA and JA-Ile levels was coincident with a rapid decrease in the levels of the precursor 12-oxo-phytodienoic acid (OPDA). The propagation of a stimulus-induced long-distance electrical signal, variation potential (VP), which is accompanied by intracellular changes in pH and Ca2+ levels, preceded systemic changes in jasmonate content. The decrease in pH during VP, mediated by transient inactivation of the plasma membrane H+-ATPase, induced the conversion of OPDA to JA, probably by regulating the availability of the OPDA substrate to JA biosynthetic enzymes. The regulation of systemic synthesis of JA and JA-Ile by the Ca2+ wave accompanying VP most likely occurs by the same mechanism of pH-induced conversion of OPDA to JA due to Ca2+-mediated decrease in pH as a result of H+-ATPase inactivation. Thus, the transient increase in intracellular Ca2+ levels and the transient decrease in intracellular pH are most likely the key mechanisms of VP-mediated regulation of jasmonate production in systemic tissues upon local stimulation.

A pH Fingerprint Assay to Identify Inhibitors of Multiple Validated and Potential Antimalarial Drug Targets.

New drugs with novel modes of action are needed to safeguard malaria treatment. In recent years, millions of compounds have been tested for their ability to inhibit the growth of asexual blood-stage Plasmodium falciparum parasites, resulting in the identification of thousands of compounds with antiplasmodial activity. Determining the mechanisms of action of antiplasmodial compounds informs their further development, but remains challenging. A relatively high proportion of compounds identified as killing asexual blood-stage parasites show evidence of targeting the parasite's plasma membrane Na+-extruding, H+-importing pump, PfATP4. Inhibitors of PfATP4 give rise to characteristic changes in the parasite's internal [Na+] and pH. Here, we designed a "pH fingerprint" assay that robustly identifies PfATP4 inhibitors while simultaneously allowing the detection of (and discrimination between) inhibitors of the lactate:H+ transporter PfFNT, which is a validated antimalarial drug target, and the V-type H+ ATPase, which was suggested as a possible target of the clinical candidate ZY19489. In our pH fingerprint assays and subsequent secondary assays, ZY19489 did not show evidence for the inhibition of pH regulation by the V-type H+ ATPase, suggesting that it has a different mode of action in the parasite. The pH fingerprint assay also has the potential to identify protonophores, inhibitors of the acid-loading Cl- transporter(s) (for which the molecular identity(ies) remain elusive), and compounds that act through inhibition of either the glucose transporter PfHT or glycolysis. The pH fingerprint assay therefore provides an efficient starting point to match a proportion of antiplasmodial compounds with their mechanisms of action.

Engineering of IF1 -susceptive bacterial F1 -ATPase.

IF1 , an inhibitor protein of mitochondrial ATP synthase, suppresses ATP hydrolytic activity of F1 . One of the unique features of IF1 is the selective inhibition in mitochondrial F1 (MF1 ); it inhibits catalysis of MF1 but does not affect F1 with bacterial origin despite high sequence homology between MF1 and bacterial F1 . Here, we aimed to engineer thermophilic Bacillus F1 (TF1 ) to confer the susceptibility to IF1 for elucidating the molecular mechanism of selective inhibition of IF1 . We first examined the IF1 -susceptibility of hybrid F1 s, composed of each subunit originating from bovine MF1 (bMF1 ) or TF1 . It was clearly shown that only the hybrid with the ß subunit of mitochondrial origin has the IF1 -susceptibility. Based on structural analysis and sequence alignment of bMF1 and TF1 , the five non-conserved residues on the C-terminus of the ß subunit were identified as the candidate responsible for the IF1 -susceptibility. These residues in TF1 were substituted with the bMF1 residues. The resultant mutant TF1 showed evident IF1 -susceptibility. Reversely, we examined the bMF1 mutant with TF1 residues at the corresponding sites, which showed significant suppression of IF1 -susceptibility, confirming the critical role of these residues. We also tested additional three substitutions with bMF1 residues in α and γ subunits that further enhanced the IF1 -susceptibility, suggesting the additive role of these residues. We discuss the molecular mechanism by which IF1 specifically recognizes F1 with mitochondrial origin, based on the present result and the structure of F1 -IF1 complex. These findings would help the development of the inhibitors targeting bacterial F1 .

Mechanism of proton-powered c-ring rotation in a mitochondrial ATP synthase.

Proton-powered c-ring rotation in mitochondrial ATP synthase is crucial to convert the transmembrane protonmotive force into torque to drive the synthesis of adenosine triphosphate (ATP). Capitalizing on recent cryo-EM structures, we aim at a structural and energetic understanding of how functional directional rotation is achieved. We performed multi-microsecond atomistic simulations to determine the free energy profiles along the c-ring rotation angle before and after the arrival of a new proton. Our results reveal that rotation proceeds by dynamic sliding of the ring over the a-subunit surface, during which interactions with conserved polar residues stabilize distinct intermediates. Ordered water chains line up for a Grotthuss-type proton transfer in one of these intermediates. After proton transfer, a high barrier prevents backward rotation and an overall drop in free energy favors forward rotation, ensuring the directionality of c-ring rotation required for the thermodynamically disfavored ATP synthesis. The essential arginine of the a-subunit stabilizes the rotated configuration through a salt bridge with the c-ring. Overall, we describe a complete mechanism for the rotation step of the ATP synthase rotor, thereby illuminating a process critical to all life at atomic resolution.

Transceptor NRT1.1 and receptor-kinase QSK1 complex controls PM H+-ATPase activity under low nitrate.

NRT1.1, a nitrate transceptor, plays an important role in nitrate binding, sensing, and nitrate-dependent lateral root (LR) morphology. However, little is known about NRT1.1-mediated nitrate signaling transduction through plasma membrane (PM)-localized proteins. Through in-depth phosphoproteome profiling using membranes of Arabidopsis roots, we identified receptor kinase QSK1 and plasma membrane H+-ATPase AHA2 as potential downstream components of NRT1.1 signaling in a mild low-nitrate (LN)-dependent manner. QSK1, as a functional kinase and molecular link, physically interacts with NRT1.1 and AHA2 at LN and specifically phosphorylates AHA2 at S899. Importantly, we found that LN, not high nitrate (HN), induces formation of the NRT1.1-QSK1-AHA2 complex in order to repress the proton efflux into the apoplast by increased phosphorylation of AHA2 at S899. Loss of either NRT1.1 or QSK1 thus results in a higher T947/S899 phosphorylation ratio on AHA2, leading to enhanced pump activity and longer LRs under LN. Our results uncover a regulatory mechanism in which NRT1.1, under LN conditions, promotes coreceptor QSK1 phosphorylation and enhances the NRT1.1-QSK1 complex formation to transduce LN sensing to the PM H+-ATPase AHA2, controlling the phosphorylation ratio of activating and inhibitory phosphorylation sites on AHA2. This then results in altered proton pump activity, apoplast acidification, and regulation of NRT1.1-mediated LR growth.

A novel lectin receptor kinase gene, AtG-LecRK-I.2, enhances bacterial pathogen resistance through regulation of stomatal immunity in Arabidopsis.

The S-locus lectin receptor kinases (G-LecRKs) have been suggested as receptors for microbe/damage-associated molecular patterns (MAMPs/DAMPs) and to be involved in the pathogen defense responses, but the functions of most G-LecRKs in biotic stress response have not been characterized. Here, we identified a member of this family, G-LecRK-I.2, that positively regulates flg22- and Pseudomonas syringae pv. tomato (Pst) DC3000-induced stomatal closure. G-LecRK-I.2 was rapidly phosphorylated under flg22 treatment and could interact with the FLS2/BAK1 complex. Two T-DNA insertion lines, glecrk-i.2-1 and glecrk-i.2-2, had lower levels of reactive oxygen species (ROS) and nitric oxide (NO) production in guard cells, as compared with the wild-type Col-0, under Pst DC3000 infection. Also, the immunity marker genes CBP60g and PR1 were induced at lower levels under Pst DC3000 hrcC- infection in glecrk-i.2-1 and glecrk-i.2-2. The GUS reporter system also revealed that G-LecRK-I.2 was expressed only in guard cells. We also found that G-LecRK-I.2 could interact H+-ATPase AHA1 to regulate H+-ATPase activity in the guard cells. Taken together, our results show that G-LecRK-I.2 plays an important role in regulating stomatal closure under flg22 and Pst DC3000 treatments and in ROS and NO signaling specifically in guard cells.

Arabidopsis COP1 guides stomatal response in guard cells through pH regulation.

Plants rely on precise regulation of their stomatal pores to effectively carry out photosynthesis while managing water status. The Arabidopsis CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), a critical light signaling repressor, is known to repress stomatal opening, but the exact cellular mechanisms remain unknown. Here, we show that COP1 regulates stomatal movement by controlling the pH levels in guard cells. cop1-4 mutants have larger stomatal apertures and disrupted pH dynamics within guard cells, characterized by increased vacuolar and cytosolic pH and reduced apoplastic pH, leading to abnormal stomatal responses. The altered pH profiles are attributed to the increased plasma membrane (PM) H+-ATPase activity of cop1-4 mutants. Moreover, cop1-4 mutants resist to growth defect caused by alkali stress posed on roots. Overall, our study highlights the crucial role of COP1 in maintaining pH homeostasis of guard cells by regulating PM H+-ATPase activity, and demonstrates how proton movement affects stomatal movement and plant growth.

Phosphorylation of plasma membrane H+-ATPase Thr881 participates in light-induced stomatal opening.

Plasma membrane (PM) H+-ATPase is crucial for light-induced stomatal opening and phosphorylation of a penultimate residue, Thr948 (pen-Thr, numbering according to Arabidopsis AHA1) is required for enzyme activation. In this study, a comprehensive phosphoproteomic analysis using guard cell protoplasts from Vicia faba shows that both red and blue light increase the phosphorylation of Thr881, of PM H+-ATPase. Light-induced stomatal opening and the blue light-induced increase in stomatal conductance are reduced in transgenic Arabidopsis plants expressing mutant AHA1-T881A in aha1-9, whereas the blue light-induced phosphorylation of pen-Thr is unaffected. Auxin and photosynthetically active radiation induce the phosphorylation of both Thr881 and pen-Thr in etiolated seedlings and leaves, respectively. The dephosphorylation of phosphorylated Thr881 and pen-Thr are mediated by type 2 C protein phosphatase clade D isoforms. Taken together, Thr881 phosphorylation, in addition of the pen-Thr phosphorylation, are important for PM H+-ATPase function during physiological responses, such as light-induced stomatal opening in Arabidopsis thaliana.

Light-induced stomatal opening requires phosphorylation of the C-terminal autoinhibitory domain of plasma membrane H+-ATPase.

Plasma membrane H+-ATPase provides the driving force for light-induced stomatal opening. However, the mechanisms underlying the regulation of its activity remain unclear. Here, we show that the phosphorylation of two Thr residues in the C-terminal autoinhibitory domain is crucial for H+-ATPase activation and stomatal opening in Arabidopsis thaliana. Using phosphoproteome analysis, we show that blue light induces the phosphorylation of Thr-881 within the C-terminal region I, in addition to penultimate Thr-948 in AUTOINHIBITED H+-ATPASE 1 (AHA1). Based on site-directed mutagenesis experiments, phosphorylation of both Thr residues is essential for H+ pumping and stomatal opening in response to blue light. Thr-948 phosphorylation is a prerequisite for Thr-881 phosphorylation by blue light. Additionally, red light-driven guard cell photosynthesis induces Thr-881 phosphorylation, possibly contributing to red light-dependent stomatal opening. Our findings provide mechanistic insights into H+-ATPase activation that exploits the ion transport across the plasma membrane and light signalling network in guard cells.

Role of root plasma membrane H+-ATPase in enhancing Cucumis sativus adaptation to microcystins.

Microcystins (MCs) are the most widespread and hazardous cyanotoxins posing a huge threat to agro-ecosystem by irrigation. Some adaptive metabolisms can be initiated at the cellular and molecular levels of plant to survive environmental change. To find ways to improve plant tolerance to MCs after recognizing adaptive mechanism in plant, we studied effects of MCs on root morphology, mineral element contents, root activity, H+-ATPase activity, and its gene expression level in cucumber during exposure and recovery (without MCs) periods. After being exposed to MCs (1, 10, 100 and 1000 µg L-1) for 7 days, we found 1 µg L-1 MCs did not affect growth and mineral elements in cucumber. MCs at 10 µg ·L-1 increased root activity and H+-ATPase activity partly from upregulation of genes (CsHA2, CsHA3, CsHA8, and CsHA9) expression, to promote nutrient uptake. Then, the increase in NO3-, Fe, Zn, and Mn contents could contribute to maintaining root growth and morphology. Higher concentration MCs (100 or 1000 µg L-1) inhibited root activity and H+-ATPase activity by downregulating expression of genes (CsHA2, CsHA3, CsHA4, CsHA8, CsHA9, and CsHA10), decreased contents of nutrient elements except Ca largely, and caused root growing worse. After a recovery, the absorption activity and H+-ATPase activity in cucumber treated with10 µg L-1 MCs were closed to the control whereas all parameters in cucumber treated 1000 µg L-1 MCs were even worse. All results indicate that the increase in H+-ATPase activity can enhance cucumber tolerance to MC stress by regulating nutrient uptake, especially when the MCs occur at low concentrations.

Regulation of metabolism and proton motive force generation during mixed carbon fermentation by an Escherichia coli strain lacking the FOF1-ATPase.

Proton FOF1-ATPase is the key enzyme in E. coli under fermentative conditions. In this study the role of E. coli proton ATPase in the µ and formation of metabolic pathways during the fermentation of mixture of glucose, glycerol and formate using the DK8 (lacking FOF1) mutant strain was investigated. It was shown that the contribution of FOF1-ATPase in the specific growth rate was ∼45 %. Formate was not taken up in the DK8 strain during the initial hours of the growth. The utilization rates of glucose and glycerol were unchanged in DK8, however, the production of succinate, lactate and ethanol was decreased causing a reduction of the redox state up to -450 mV. Moreover, the contribution of FOF1-ATPase in the interplay between H+ and H2 cycles was described depending on the bacterial growth phase and main utilizing substrate. Besides, the H2 production rate in the DK8 strain was decreased by ∼60 % at 20 h and was absent at 72 h. Δp was decreased from -157 ± 4.8 mV to -140 ± 4.2 mV at 20 h and from -195 ± 5.9 mV to -148 ± 4.4 mV at 72 h, compared to WT. Taken together it can be concluded that during fermentation of mixed carbon sources metabolic cross talk between FOF1-ATPase-TrkA-Hyd-Fdh-H is taking place for maintaining the cell energy balance via regulation proton motive force.

Effect of NaCl on ammonium and nitrate uptake and transport in salt-tolerant and salt-sensitive poplars.

Nitrogen (N) plays an important role in mitigating salt stress in tree species. We investigate the genotypic differences in the uptake of ammonium (NH4+) and nitrate (NO3-) and the importance for salt tolerance in two contrasting poplars, salt-tolerant Populus euphratica Oliv. and salt-sensitive P. simonii × (P. pyramidalis ×Salix matsudana) (P. popularis cv. 35-44, P. popularis). Total N content, growth and photosynthesis were significantly reduced in P. popularis after 7 days of exposure to NaCl (100 mM) supplied with 1 mM NH4+ and 1 mM NO3-, while the salt effects were not pronounced in P. euphratica. The 15NH4+ trace and root flux profiles showed that salt-stressed poplars retained ammonium uptake, which was related to the upregulation of ammonium transporters (AMTs) in roots, as two of the four AMTs tested significantly increased in salt-stressed P. euphratica (i.e., AMT1.2, 2.1) and P. popularis (i.e., AMT1.1, 1.6). It should be noted that P. euphratica differs from salt-sensitive poplar in the maintenance of NO3- under salinity. 15NO3- tracing and root flux profiles showed that P. euphratica maintained nitrate uptake and transport, while the capacity to uptake NO3- was limited in salt-sensitive P. popularis. Salt increased the transcription of nitrate transporters (NRTs), NRT1.1, 1.2, 2.4, 3.1, in P. euphratica, while P. popularis showed a decrease in the transcripts of NRT1.1, 2.4, 3.1 after 7 days of salt stress. Furthermore, salt-stimulated transcription of plasmalemma H+-ATPases (HAs), HA2, HA4 and HA11 contributed to H+-pump activation and NO3- uptake in P. euphratica. However, salt stimulation of HAs was less pronounced in P. popularis, where a decrease in HA2 transcripts was observed in the stressed roots. We conclude that the salinity-decreased transcripts of NRTs and HAs reduced the ability to uptake NO3- in P. popularis, resulting in limited nitrogen supply. In comparison, P. euphratica maintains NH4+ and NO3- supply, mitigating the negative effects of salt stress.

Intein-based thermoregulated meganucleases for containment of genetic material.

Limiting the spread of synthetic genetic information outside of the intended use is essential for applications where biocontainment is critical. In particular, biocontainment of engineered probiotics and plasmids that are excreted from the mammalian gastrointestinal tract is needed to prevent escape and acquisition of genetic material that could confer a selective advantage to microbial communities. Here, we built a simple and lightweight biocontainment system that post-translationally activates a site-specific DNA endonuclease to degrade DNA at 18°C and not at higher temperatures. We constructed an orthogonal set of temperature-sensitive meganucleases (TSMs) by inserting the yeast VMA1 L212P temperature-sensitive intein into the coding regions of LAGLIDADG homing endonucleases. We showed that the TSMs eliminated plasmids carrying the cognate TSM target site from laboratory strains of Escherichia coli at the permissive 18°C but not at higher restrictive temperatures. Plasmid elimination is dependent on both TSM endonuclease activity and intein splicing. TSMs eliminated plasmids from E. coli Nissle 1917 after passage through the mouse gut when fecal resuspensions were incubated at 18°C but not at 37°C. Collectively, our data demonstrates the potential of thermoregulated meganucleases as a means of restricting engineered plasmids and probiotics to the mammalian gut.

Genome-wide profiling of piggyBac transposon insertion mutants reveals loss of the F1F0 ATPase complex causes fluconazole resistance in Candida glabrata.

Invasive candidiasis caused by non-albicans species has been on the rise, with Candida glabrata emerging as the second most common etiological agent. Candida glabrata possesses an intrinsically lower susceptibility to azoles and an alarming propensity to rapidly develop high-level azole resistance during treatment. In this study, we have developed an efficient piggyBac (PB) transposon-mediated mutagenesis system in C. glabrata to conduct genome-wide genetic screens and applied it to profile genes that contribute to azole resistance. When challenged with the antifungal drug fluconazole, PB insertion into 270 genes led to significant resistance. A large subset of these genes has a role in the mitochondria, including almost all genes encoding the subunits of the F1F0 ATPase complex. We show that deleting ATP3 or ATP22 results in increased azole resistance but does not affect susceptibility to polyenes and echinocandins. The increased azole resistance is due to increased expression of PDR1 that encodes a transcription factor known to promote drug efflux pump expression. Deleting PDR1 in the atp3Δ or atp22Δ mutant resulted in hypersensitivity to fluconazole. Our results shed light on the mechanisms contributing to azole resistance in C. glabrata. This PB transposon-mediated mutagenesis system can significantly facilitate future genome-wide genetic screens.

A novel ATP13A2 variant causing complicated hereditary spastic paraplegia.

BACKGROUND: ATP13A2 is a monogenic causative gene of Parkinson's disease, whose biallelic mutations can result in Kufor-Rakeb syndrome. Biallelic mutations in ATP13A2 have also been reported in pure or complicated hereditary spastic paraplegia (HSP). Here, we report clinical, neuroimaging, and genetic findings from a patient with a novel homozygous mutation in ATP13A2 presenting with HSP plus parkinsonism. METHODS: Whole genome sequencing was performed on the patient, a 46-year-old Chinese woman from a consanguineous family, to identify the genetic cause. Furthermore, functional studies of the identified ATP13A2 mutation were conducted. RESULTS: The patient initially presented with abnormal gait because of lower-limb spasticity and recurrent seizures. Parkinsonism (presenting as bradykinesia and rigidity) and peripheral neuropathy in lower limbs further evolved and resulted in her eventual use of a wheelchair. Symmetrically decreased dopamine transporter density was detected within the bilateral putamen and caudate nucleus in dopamine transporter-positron emission tomography. Genetic analysis revealed a novel homozygous missense mutation in ATP13A2 (c.2780 T > C, p.Leu927Pro), which was heterozygous in the patient's parents and son. Functional studies suggested that this mutation results in the reduced expression and altered subcellular localization of ATP13A2. CONCLUSIONS: Our report broadens the genetic and phenotypic spectrum of ATP13A2-related HSP. Further research is needed to fully elucidate the mechanism linking ATP13A2 variants to HSP.