| 2004 |
CERT catalyzes intermembrane transfer of ceramide via its START domain, with strict stereo-specificity for the natural D-erythro isomer and an acyl-chain length limit (efficient for C14–C20 but not longer chains); it does not transfer sphingosine or sphingomyelin; (1R,3R)-HPA-12 was identified as an antagonist of the CERT START domain in vitro. |
Cell-free lipid transfer assay, lipid binding assay, radiolabeled ceramide analogs |
The Journal of biological chemistry |
High |
15596449
|
| 2006 |
CERT requires both its PH domain (for Golgi targeting via PI4P) and its FFAT motif (for interaction with ER-resident VAP-A and VAP-B) for efficient ER-to-Golgi ceramide transport in cells; VAP-A and VAP-B co-immunoprecipitate with CERT and this interaction is abolished by FFAT motif mutations; neither FFAT nor PH domain mutations affect ceramide transfer activity in cell-free assays, indicating these domains spatially restrict the random transfer activity of the START domain. |
Co-immunoprecipitation, FFAT motif mutagenesis, semi-intact cell ceramide transport assay, cell-free lipid transfer assay |
The Journal of biological chemistry |
High |
16895911
|
| 2007 |
CERT activity is down-regulated by multiple phosphorylations at a serine-repeat motif (SRM), a substrate for casein kinase I; phosphorylation induces an autoinhibitory intramolecular interaction between the PH and START domains, inactivating both PI4P binding and ceramide transfer activities; loss of sphingomyelin and cholesterol causes dephosphorylation of CERT to activate it. |
In vitro phosphorylation assays, domain interaction assays, PI4P-binding assay, ceramide transfer assay, cell-based sphingomyelin depletion experiments |
The Journal of biological chemistry |
High |
17442665
|
| 2008 |
Crystal structures of the CERT START domain in apo-form and in complex with ceramides of different acyl chain lengths reveal that one ceramide molecule is buried in a long amphiphilic cavity; hydrogen-bond networks at the far end of the cavity mediate stereo-specific ceramide recognition; cavity size dictates the acyl-chain length limit; the alpha-3 helix and Omega1 loop are proposed to act as a gate for ceramide entry. |
X-ray crystallography (crystal structures of apo and ceramide-bound START domain) |
Proceedings of the National Academy of Sciences of the United States of America |
High |
18184806
|
| 2007 |
CERT is preferentially distributed to the Golgi region in cells; its PH domain specifically recognizes phosphatidylinositol 4-monophosphate (PI4P) at the Golgi for targeting; membrane contact sites between ER and Golgi are proposed as sites of efficient ceramide transfer. |
Subcellular fractionation, domain binding studies, fluorescence localization |
Biochimica et biophysica acta |
Medium |
17314061
|
| 2007 |
PP2Cepsilon, an ER-resident transmembrane phosphatase, dephosphorylates CERT in a VAPA-dependent manner; PP2Cepsilon expression causes redistribution of CERT from cytoplasm to Golgi and enhances CERT-VAPA association; PP2Cepsilon knockdown attenuates CERT-VAPA interaction and sphingomyelin synthesis, identifying CERT as a physiological substrate of PP2Cepsilon. |
Yeast two-hybrid, co-immunoprecipitation, siRNA knockdown, subcellular localization by immunofluorescence, sphingomyelin synthesis assay |
The Journal of biological chemistry |
High |
18165232
|
| 2009 |
Crystal structures of the CERT START domain bound to HPA inhibitors reveal that the Omega1 loop adopts a different conformation compared to ceramide-bound structures, with Trp473 moving inside the cavity; surface plasmon resonance confirmed that Trp473 is important for membrane interaction, suggesting a gating mechanism for ceramide loading/unloading. |
X-ray crystallography, surface plasmon resonance |
Journal of molecular biology |
High |
20036255
|
| 2011 |
Chlamydia trachomatis effector protein IncD directly binds the PH domain of CERT and recruits CERT to the inclusion membrane; this redirects ceramide trafficking toward the inclusion; CERT and VAP-A/B co-localize at ER-inclusion membrane contact sites; depletion of CERT or VAP proteins impairs bacterial development. |
Co-immunoprecipitation, ectopic expression, siRNA knockdown, immunofluorescence co-localization, bacterial development assay |
PLoS pathogens |
High |
21731489 21909260
|
| 2012 |
The CERT PH domain structure determined by solution NMR reveals a characteristic basic groove near the canonical PI4P recognition site; this basic groove coordinates efficient PI4P recognition and Golgi targeting; mutations of basic groove residues cause Golgi mislocalization in living cells. |
Solution NMR structure determination, NMR chemical shift perturbation binding assay, cell-based localization with mutants |
The Journal of biological chemistry |
High |
22869376
|
| 2014 |
Phosphorylation of CERT at serine 315, adjacent to the FFAT motif, markedly enhances CERT-VAP interaction and ER-to-Golgi ceramide transport activity; the phosphomimetic S315E mutant shows higher ceramide transport activity in a semi-intact cell system; S315 phosphorylation increases under sphingolipid depletion conditions and acts additively with SRM dephosphorylation to activate CERT. |
Semi-intact cell ceramide transport assay, co-immunoprecipitation, CERT mutant analysis, immunofluorescence, biochemical phosphorylation analysis |
The Journal of biological chemistry |
High |
24569996
|
| 2014 |
Both the N- and C-terminal cytoplasmic regions of Chlamydia IncD are required for binding to the CERT PH domain; the IncD transmembrane region forms SDS-resistant homodimers and higher-order oligomers, which may facilitate high-affinity CERT binding. |
Co-transfection and co-immunoprecipitation, native gel electrophoresis, phylogenetic analysis |
Infection and immunity / Biochemical and biophysical research communications |
Medium |
24595143 30314703
|
| 2018 |
Hyperphosphorylation-mimetic SRM substitutions (10E variant) cause an intramolecular interaction between the SRM and positively charged regions of the PH domain, directly competing with PI4P binding; this reduces PI4P-embedded membrane binding in cell-free assays and Golgi targeting in living cells. |
Solution NMR, PI4P-binding assay, fluorescence Golgi targeting assay in cells |
The Journal of biological chemistry |
High |
29848549
|
| 2016 |
Targeting ceramide transport from ER to mitochondria using a mitoCERT construct (CERT with an outer mitochondrial membrane anchor) induces Bax-dependent apoptosis; apoptosis requires the ceramide transfer domain, VAP interaction via the ER, de novo ceramide synthesis, and is abolished by a bacterial ceramidase targeted to mitochondria — demonstrating that ER ceramide translocation to mitochondria directly commits cells to apoptosis. |
Engineered mitoCERT construct, domain deletion and FFAT mutants, CERT inhibitor HPA-12, de novo ceramide synthesis inhibition, mitochondria-targeted ceramidase, cell death assays |
Journal of cell science |
High |
27888218
|
| 2008 |
UVB irradiation induces formation of a stable CERT homotrimer complex in keratinocytes and other cell lines; the homotrimer formation requires the middle region domain of CERT (not the PH or START domains); CERT in the homotrimer has decreased ceramide binding activity; homotrimer formation correlates with decreased sphingomyelin synthesis and increased apoptosis. |
Western immunoblot, mass spectrometry, ceramide binding assay, siRNA knockdown, CERT inhibitor HPA-12 |
The Journal of biological chemistry |
Medium |
18411267
|
| 2019 |
CERT function is down-regulated by multisite SRM phosphorylation primed by protein kinase D (activated by diacylglycerol produced during ceramide-to-sphingomyelin conversion), creating a feedback mechanism; S315 phosphorylation enhances CERT-VAP binding; the PI4P pool at trans-Golgi (regulated by PI4-kinases and OSBP) controls CERT-dependent ceramide transport. |
Biochemical phosphorylation analysis, cell-based assays, lipid measurement (review of experimental findings) |
FEBS letters |
Medium |
31254361
|
| 2018 |
CERT (STARD11) mediates palmitate-stimulated extracellular vesicle/exosome biogenesis in liver cells; STARD11-deficient cells release fewer extracellular vesicles, exhibit intracellular ceramide accumulation, and show reduced cellular viability; STARD11 co-localizes with ER and multivesicular bodies. |
STARD11 knockout cell lines, extracellular vesicle quantification, ceramide measurement, immunofluorescence co-localization |
The Journal of biological chemistry |
Medium |
30139741
|
| 2020 |
De novo missense variants in CERT1 causing intellectual disability include gain-of-function mutations (e.g., S135P) that impair SRM hyperphosphorylation and thus prevent down-regulation of CERT activity; these mutations cause abnormal CERT activation and punctate subcellular redistribution. |
Whole exome sequencing, biochemical analysis of SRM phosphorylation, subcellular localization imaging |
PloS one |
Medium |
33347465
|
| 2021 |
ID-associated CERT1 mutations S132L and G243R impair SRM hyperphosphorylation, rendering the proteins excessively active and causing punctate subcellular redistribution; a frameshift variant (dupAA) that does not impair SRM phosphorylation does not cause aberrant activity or localization, serving as a disease-matched negative control. |
Biochemical phosphorylation analysis, subcellular localization imaging, patient variant characterization |
The Journal of biological chemistry |
Medium |
34688657
|
| 2022 |
A previously uncharacterized cluster of lysine/arginine residues on the outer surface of a coiled-coil region of CERT is involved in SRM phosphorylation-dependent repression of CERT function; alanine substitutions in this cluster release repression of SM synthesis, PI4P-binding, VAP binding, ceramide transfer, and Golgi localization, and partially destabilize the CERT trimer. |
Site-directed mutagenesis, SM synthesis assay, PI4P-binding assay, VAP co-IP, ceramide transfer assay, subcellular localization |
International journal of molecular sciences |
Medium |
35955719
|
| 2022 |
Hyperosmotic stress induces S315 phosphorylation of CERT without altering SRM phosphorylation; under these conditions, CERT-VAP-A binding is enhanced throughout the ER (not only at ER-Golgi MCS), demonstrating that S315 phosphorylation and SRM dephosphorylation can be uncoupled and that they have distinct spatial consequences. |
Biochemical phosphorylation analysis, co-immunoprecipitation, immunofluorescence subcellular localization |
International journal of molecular sciences |
Medium |
35409383
|
| 2022 |
HSV-1 pUL21, a viral phosphatase adaptor, directly interacts with CERT with submicromolar affinity; pUL21 promotes dephosphorylation of CERT, activating it and accelerating ceramide-to-sphingomyelin conversion; solution structure of the pUL21 C-terminal domain in complex with CERT PH and START domains was determined by SAXS; a single conserved pUL21 surface residue disrupts CERT binding in vitro and in cells. |
Click chemistry sphingolipid profiling, surface plasmon resonance, small-angle X-ray scattering (SAXS), site-directed mutagenesis, co-immunoprecipitation |
The Journal of biological chemistry |
High |
36243114
|
| 2023 |
Several CERT1 intellectual disability variants fall in a previously uncharacterized dimeric helical domain that enables CERT homeostatic autoregulation/inactivation; disruption of this domain by de novo missense variants causes unchecked sphingolipid production; pharmacological CERT inhibition corrects morphological and motor abnormalities in a Drosophila model. |
Structural characterization of dimeric helical domain, patient variant analysis, Drosophila model with pharmacological rescue |
The Journal of clinical investigation |
High |
36976648
|
| 2022 |
VAP-A and its binding partner CERT localize to multivesicular bodies (MVBs); knockdown of CERT or VAP-A reduces RNA content of small extracellular vesicles and ceramide in EVs; ceramide generated via the VAP-A/CERT axis at ER-MVB membrane contact sites drives biogenesis of a select RNA-containing EV population. |
siRNA knockdown, EV isolation and RNA/lipid profiling, live imaging, colocalization experiments |
Developmental cell |
Medium |
35421371
|
| 2023 |
CERT preferentially utilizes PI4P generated by PI4KB recruited to the Golgi by C10orf76 (rather than ACBD3) for ceramide transport; super-resolution microscopy shows C10orf76 localizes predominantly at distal Golgi where sphingomyelin synthesis primarily occurs, while ACBD3 is at more proximal regions — establishing a C10orf76-PI4KB axis that orchestrates CERT-mediated ceramide delivery to distal Golgi. |
Genome-wide screening, PI4P measurement, super-resolution microscopy, knockdown/knockout of PI4KB, ACBD3, C10orf76 |
The Journal of cell biology |
High |
37195633
|
| 2023 |
CERT mediates intermembrane transfer of alkylacylglycerol (AAG) in vitro; CERT inhibition (HPA-12) or START domain deletion abolishes AAG transfer; CERT suppression in HEK293 cells increases plasmanyl-PC levels (an AAG metabolite), and CERT re-introduction reduces these levels — identifying CERT as a transporter of AAG from ER to Golgi for ether phospholipid biosynthesis. |
In vitro lipid transfer assay, HPA-12 inhibition, domain deletion, CERT knockdown/rescue, cellular lipid measurement |
Archives of biochemistry and biophysics |
Medium |
38110110
|
| 2024 |
Molecular dynamics simulations propose a membrane-assisted mechanism for ceramide release from the CERT START domain, in which membrane contact acts as allosteric effector and a single phosphatidylcholine lipid intercalates into the START cavity to facilitate ceramide egress; free energy calculations and experimental lipidomics confirmed CERT forms stable complexes with phosphatidylcholine in addition to ceramide. |
Molecular dynamics simulations, free energy calculations, experimental lipidomics |
The journal of physical chemistry B |
Low |
38903016
|
| 2010 |
Human biliverdin reductase (hBVR) binds to GPBP (CERT1 long isoform) and down-regulates its TNF-alpha-stimulated kinase activity in HEK293A cells; hBVR siRNA knockdown modulates TNF-alpha/NF-κB-stimulated GPBP expression; the interacting domain was mapped to the C-terminal CX10C motif of hBVR. |
Co-immunoprecipitation, siRNA knockdown, kinase activity assay, peptide mapping |
The Journal of biological chemistry |
Medium |
20177069
|
| 2011 |
GPBP-1 (the long isoform of CERT1) accumulates in cytoplasm of differentiating myoblasts prior to myosin synthesis; GPBP-1-deficient myoblasts show defective myofibril formation; GPBP-1 targets GIP130 (a 130-kDa interacting protein), which binds myosin and promotes its myofibrillar assembly. |
Loss-of-function (deficiency), overexpression, co-immunoprecipitation (GPBP-GIP130), myofibril formation assay |
The Journal of biological chemistry |
Medium |
21832087
|
| 2021 |
CERTL (long isoform) binds to amyloid precursor protein (APP) as shown by co-immunoprecipitation; recombinant CERTL modifies Aβ aggregation and reduces Aβ neurotoxicity in neuroblastoma cells; CERTL overexpression in 5xFAD mouse brains reduces ceramide d18:1/16:0 levels, increases sphingomyelin, decreases Aβ formation, and modulates microglia toward a less pro-inflammatory phenotype. |
Co-immunoprecipitation, immunofluorescence, AAV-mediated overexpression in mice, mass spectrometry lipidomics, immunohistochemistry, behavior tests |
Alzheimer's research & therapy |
Medium |
33597019
|
| 2018 |
CERT protein expression is reduced in insulin-resistance models via caspase-dependent cleavage; inhibiting CERT activity potentiates lipotoxicity-induced insulin signaling defects; CERT overexpression in vitro and in vivo decreases muscle ceramide content and improves insulin signaling; inhibition of caspase activity prevents ceramide-induced insulin signaling defects. |
CERT knockdown/overexpression in muscle cells, in vivo overexpression, insulin signaling assays, ceramide measurement, caspase inhibition |
Diabetes |
Medium |
29759974
|
| 2017 |
C. psittaci recruits CERT to its inclusion; CERT knockout (CRISPR/Cas9) impairs C. psittaci infection, affecting inclusion growth and infectious progeny formation; CERT-independent sphingolipid uptake pathways exist in CERT-KO cells, and HPA-12 sensitive factors beyond CERT are involved in sphingolipid trafficking to C. psittaci. |
CRISPR/Cas9 CERT knockout, CERT chemical inhibition (HPA-12), fluorescent sphingolipid uptake assay, bacterial development quantification |
Cellular microbiology |
Medium |
28544656
|
| 2025 |
In Drosophila, loss of dcert leads to elevated short-chain ceramide and reduced phosphatidylethanolamine ceramide; dcert mutants show reduced photoreceptor electrical responses to light and impaired PIP2 resynthesis following PLC activation; reducing ceramide synthesis at the ER suppresses the dcert light response phenotype — establishing that CERT-mediated ceramide transfer from ER to Golgi regulates G-protein coupled phospholipase C signaling in vivo. |
Loss-of-function alleles, electrophysiology (ERG), lipidomics, genetic suppressor (ceramide synthesis reduction), rescue with wild-type gene |
bioRxivpreprint |
Medium |
|