CRD1 (CLS1) encodes the eukaryotic-type cardiolipin synthase (CMP-forming, EC 2.7.8.41) of Saccharomyces cerevisiae, a multi-pass protein of the mitochondrial inner membrane belonging to the CDP-alcohol phosphatidyltransferase family. It transfers the phosphatidyl group of CDP-diacylglycerol to phosphatidylglycerol, forming cardiolipin (CL) and CMP; the reaction requires a divalent cation (Mg2+) and the substrates are supplied in the inner membrane by Tam41 (CDP-DAG) and the Pgs1-Gep4 pathway (PG). Crd1 is the only CL synthase in yeast: crd1 null cells lack CL and accumulate PG. CL is required for optimal mitochondrial membrane potential, respiratory function, protein import and mtDNA stability at elevated temperature, and its loss also produces secondary defects such as impaired vacuolar acidification and mislocalisation of CL-binding proteins like Ups1. Crd1 is distinct from the bacterial phospholipase D-type cardiolipin synthases that condense two PG molecules. Cardiolipin made by Crd1 is also needed for efficient biogenesis of multispan outer-membrane proteins such as Ugo1, Scm4 and Om14, and cardiolipin and mitochondrial phosphatidylethanolamine have overlapping roles in keeping mitochondria tubular and fusion-competent, so that loss of both, but not of cardiolipin alone, fragments the network.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005739 mitochondrion | HDA PMID:16823961 Toward the complete yeast mitochondrial proteome: multidimen... | ACCEPT | Summary: Detected in the PROMITO high-coverage mitochondrial proteome. Correct; Crd1 is an inner membrane protein. Supporting Evidence: PMID:16823961 A total of 851 different proteins (PROMITO dataset) were identified by use of multidimensional LC-MS/MS |
| GO:0005739 mitochondrion | IBA GO_REF:0000033 | ACCEPT | Summary: IBA is_active_in mitochondrion from CLS orthologues (human CRLS1, Arabidopsis, S. pombe). Correct. Supporting Evidence: PMID:9614098 CL and its synthesis are localized predominantly to the mitochondrial inner membrane |
| GO:0005739 mitochondrion | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (PHOS-PWY) placing CL synthase activity in mitochondria. Correct compartment (more precisely the inner membrane). Supporting Evidence: PMID:2171667 Cardiolipin (CL) synthase activity was characterized in mitochondrial extracts of the yeast Saccharomyces cerevisiae and was shown for the first time to utilize CDP-diacylglycerol as a substrate. |
| GO:0005743 mitochondrial inner membrane | IEA GO_REF:0000044 | ACCEPT | Summary: UniProt subcellular location (SL-0168) mitochondrion inner membrane. Correct and most precise location. Supporting Evidence: file:yeast/CRD1/CRD1-uniprot.txt SUBCELLULAR LOCATION: Mitochondrion inner membrane PMID:9614098 CL and its synthesis are localized predominantly to the mitochondrial inner membrane |
| GO:0005743 mitochondrial inner membrane | ISS GO_REF:0000024 | ACCEPT | Summary: ISS from Arabidopsis CLS (Q93YW7), which localises to the mitochondrial inner membrane. Consistent with yeast data. Supporting Evidence: PMID:9614098 CL and its synthesis are localized predominantly to the mitochondrial inner membrane |
| GO:0005829 cytosol | RCA GO_REF:0000123 | MODIFY | Summary: YeastPathways RCA (PHOSLIPSYN2-PWY-1) places cardiolipin synthase activity in the cytosol by pathway default. Crd1 is an integral mitochondrial inner membrane enzyme; the activity is not cytosolic. Reason: Wrong compartment from pathway default. Proposed replacements: mitochondrial inner membrane Supporting Evidence: PMID:9614098 CL and its synthesis are localized predominantly to the mitochondrial inner membrane |
| GO:0005829 cytosol | RCA GO_REF:0000123 | MODIFY | Summary: YeastPathways RCA (PWY3O-2) places cardiolipin synthase activity in the cytosol by pathway default. Crd1 is an integral mitochondrial inner membrane enzyme; the activity is not cytosolic. Reason: Wrong compartment from pathway default. Proposed replacements: mitochondrial inner membrane Supporting Evidence: PMID:9614098 CL and its synthesis are localized predominantly to the mitochondrial inner membrane |
| GO:0006612 protein targeting to membrane | IMP PMID:26235513 Structural and mechanistic insights into phospholipid transf... | MARK AS OVER ANNOTATED | Summary: Watanabe et al. found that the lipid-transfer protein Ups1 partitions to inner-membrane vesicles in wild-type mitochondria but is evenly distributed between outer and inner membrane vesicles in crd1 mitochondria lacking CL. The result shows CL (the product) influences Ups1 membrane association; Crd1 itself does not target proteins to membranes. The effect is a downstream consequence of CL synthesis. Reason: Indirect, product-mediated effect; Crd1 does not perform protein targeting. Supporting Evidence: PMID:26235513 Ups1 was recovered exclusively in the IM vesicles in WT mitochondria, while it was evenly distributed to the OM and IM vesicles in crd1Ξ mitochondria lacking cardiolipin |
| GO:0006644 phospholipid metabolic process | IEA GO_REF:0000117 | TOO GENERAL | Summary: ARBA annotation to phospholipid metabolic process; correct but general. Supporting Evidence: file:yeast/CRD1/CRD1-uniprot.txt FUNCTION: Catalyzes the synthesis of cardiolipin (CL) |
| GO:0006644 phospholipid metabolic process | IMP PMID:27402848 Misregulation of a DDHD Domain-containing Lipase Causes Mito... | TOO GENERAL | Summary: Yadav et al. used crd1 cells (no CL, elevated PG) as controls in a study of the DDHD lipase Ddl1; crd1 deletion alters PG/CL phospholipid composition. Correct but general; the precise process is CL biosynthesis. Supporting Evidence: PMID:27402848 The crd1 Ξ cells grown on glucose showed an accumulation of PG |
| GO:0006873 intracellular monoatomic ion homeostasis | IMP PMID:18799619 Cardiolipin mediates cross-talk between mitochondria and the... | KEEP AS NON CORE | Summary: crd1 mutants show swollen vacuoles, loss of vacuolar acidification and reduced V-ATPase activity at 37C, rescued by rtg2 or nhx1 deletion. This is a downstream consequence of CL deficiency rather than a direct function of the synthase; retained as non-core in deference to the curator. Reason: Indirect pleiotropic phenotype of CL loss. Supporting Evidence: PMID:18799619 we present evidence that the crd1Delta mutant exhibits severe vacuolar defects, including swollen vacuole morphology and loss of vacuolar acidification, at 37 degrees C. |
| GO:0007006 mitochondrial membrane organization | IMP PMID:10777514 Absence of cardiolipin in the crd1 null mutant results in de... | KEEP AS NON CORE | Summary: crd1 null mutants lack CL and have decreased mitochondrial membrane potential, impaired protein import and respiratory defects. Synthesising CL, a structural lipid of the inner membrane, contributes to mitochondrial membrane organisation; non-core relative to the catalytic function. Reason: Consequence of CL synthesis; non-core. Supporting Evidence: PMID:10777514 Saccharomyces cerevisiae cells containing a disruption of CRD1, the structural gene encoding CL synthase, have no CL in mitochondrial membranes. PMID:10777514 We propose that CL is required for maintaining the mitochondrial membrane potential and that reduced membrane potential in the absence of CL leads to defects in protein import and other mitochondrial functions. |
| GO:0008610 lipid biosynthetic process | IDA PMID:7564918 Kinetic analysis of cardiolipin synthase: a membrane enzyme ... | MODIFY | Summary: Schlame et al. partially purified CL synthase from yeast mitochondria and showed it transfers a phosphatidyl moiety from CDP-DAG to PG. The evidence is correct but 'lipid biosynthetic process' is far too general; the specific process is cardiolipin biosynthesis. Reason: Replace general term with the specific process demonstrated. Proposed replacements: cardiolipin biosynthetic process Supporting Evidence: PMID:7564918 Mitochondrial cardiolipin synthase catalyzes the transfer of a phosphatidyl moiety from phosphatidyl-CMP (PtdCMP) to phosphatidylglycerol (PtdGro) in the presence of specific divalent cations. PMID:7564918 The synthase was solubilized from Saccharomyces cerevisiae mitochondria and purified about 300-fold. |
| GO:0008610 lipid biosynthetic process | IEA GO_REF:0000117 | MODIFY | Summary: ARBA annotation to lipid biosynthetic process; correct but uninformative. Cardiolipin biosynthetic process is the specific process. Reason: Too general. Proposed replacements: cardiolipin biosynthetic process Supporting Evidence: file:yeast/CRD1/CRD1-uniprot.txt FUNCTION: Catalyzes the synthesis of cardiolipin (CL) |
| GO:0008610 lipid biosynthetic process | IMP PMID:9614098 Isolation and characterization of the gene (CLS1) encoding c... | MODIFY | Summary: CLS1/CRD1 disruption abolished CL synthase activity and CL, while overexpression raised activity. Correct evidence, overly general term; replace with cardiolipin biosynthetic process. Reason: Too general. Proposed replacements: cardiolipin biosynthetic process Supporting Evidence: PMID:9614098 Disruption of the CLS1 gene in a haploid yeast strain resulted in the loss of CL synthase activity, no detectable CL, a 5-fold elevation in phosphatidylglycerol levels |
| GO:0008654 phospholipid biosynthetic process | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro IPR000462 mapping to phospholipid biosynthetic process. Correct general process. Supporting Evidence: file:yeast/CRD1/CRD1-uniprot.txt FUNCTION: Catalyzes the synthesis of cardiolipin (CL) |
| GO:0008654 phospholipid biosynthetic process | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (PHOS-PWY) to phospholipid biosynthetic process. Correct general process; the precise process is cardiolipin biosynthesis. Supporting Evidence: PMID:9614098 Disruption of the CLS1 gene in a haploid yeast strain resulted in the loss of CL synthase activity, no detectable CL, a 5-fold elevation in phosphatidylglycerol levels |
| GO:0008654 phospholipid biosynthetic process | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (PHOSLIPSYN2-PWY-1) to phospholipid biosynthetic process. Correct general process; the precise process is cardiolipin biosynthesis. Supporting Evidence: PMID:9614098 Disruption of the CLS1 gene in a haploid yeast strain resulted in the loss of CL synthase activity, no detectable CL, a 5-fold elevation in phosphatidylglycerol levels |
| GO:0008654 phospholipid biosynthetic process | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (PWY3O-2) to phospholipid biosynthetic process. Correct general process; the precise process is cardiolipin biosynthesis. Supporting Evidence: PMID:9614098 Disruption of the CLS1 gene in a haploid yeast strain resulted in the loss of CL synthase activity, no detectable CL, a 5-fold elevation in phosphatidylglycerol levels |
| GO:0016020 membrane | IEA GO_REF:0000002 | TOO GENERAL | Summary: InterPro-based membrane annotation; correct but general (mitochondrial inner membrane). Supporting Evidence: file:yeast/CRD1/CRD1-uniprot.txt SUBCELLULAR LOCATION: Mitochondrion inner membrane |
| GO:0016780 phosphotransferase activity, for other substituted phosphate groups | IEA GO_REF:0000120 | ACCEPT | Summary: ARBA/InterPro IPR000462 mapping to phosphotransferase activity, for other substituted phosphate groups. Correct parent of CL synthase (CMP-forming) activity. Supporting Evidence: file:yeast/CRD1/CRD1-uniprot.txt FUNCTION: Catalyzes the synthesis of cardiolipin (CL) |
| GO:0032049 cardiolipin biosynthetic process | IBA GO_REF:0000033 | ACCEPT | Summary: IBA for cardiolipin biosynthetic process (PTN000370438) from CLS orthologues. Core process; supported in yeast by loss of CL in crd1 mutants. Supporting Evidence: PMID:9614098 Disruption of the CLS1 gene in a haploid yeast strain resulted in the loss of CL synthase activity, no detectable CL, a 5-fold elevation in phosphatidylglycerol levels PMID:10777514 Saccharomyces cerevisiae cells containing a disruption of CRD1, the structural gene encoding CL synthase, have no CL in mitochondrial membranes. |
| GO:0043337 cardiolipin synthase (CMP-forming) activity | EXP PMID:2171667 Biochemical characterization and regulation of cardiolipin s... | ACCEPT | Summary: Tamai and Greenberg characterised CL synthase in yeast mitochondrial extracts and showed it uses CDP-DAG as the phosphatidyl donor (CMP-forming). Supporting Evidence: PMID:2171667 Cardiolipin (CL) synthase activity was characterized in mitochondrial extracts of the yeast Saccharomyces cerevisiae and was shown for the first time to utilize CDP-diacylglycerol as a substrate. |
| GO:0043337 cardiolipin synthase (CMP-forming) activity | EXP PMID:9370334 Cardiolipin synthase from yeast. | ACCEPT | Summary: Schlame and Greenberg review/characterisation of purified yeast CL synthase (25-30 kDa protein) forming a ternary complex with its two lipid substrates. Supporting Evidence: PMID:9370334 Cardiolipin synthase catalyzes the synthesis of the mitochondrial phospholipid cardiolipin. PMID:9370334 Enzyme activity was associated with a 25-30-kDa protein. |
| GO:0043337 cardiolipin synthase (CMP-forming) activity | IBA GO_REF:0000033 | ACCEPT | Summary: IBA (PTN000370438) from eukaryotic CLS orthologues including Crd1 itself (SGD:S000002301). Correct. Supporting Evidence: PMID:9614098 Overexpression of the CLS1 gene under its endogenous promoter or the inducible GAL1 promoter in yeast and expression of CLS1 in baculovirus-infected insect cells resulted in elevated CL synthase activity. |
| GO:0043337 cardiolipin synthase (CMP-forming) activity | IDA PMID:7564918 Kinetic analysis of cardiolipin synthase: a membrane enzyme ... | ACCEPT | Summary: Kinetic analysis of partially purified mitochondrial CL synthase transferring the phosphatidyl moiety from PtdCMP (CDP-DAG) to PG. Supporting Evidence: PMID:7564918 Mitochondrial cardiolipin synthase catalyzes the transfer of a phosphatidyl moiety from phosphatidyl-CMP (PtdCMP) to phosphatidylglycerol (PtdGro) in the presence of specific divalent cations. |
| GO:0043337 cardiolipin synthase (CMP-forming) activity | IEA GO_REF:0000120 | ACCEPT | Summary: RHEA:32931/EC 2.7.8.41 mapping; correct. Supporting Evidence: file:yeast/CRD1/CRD1-uniprot.txt FUNCTION: Catalyzes the synthesis of cardiolipin (CL) |
| GO:0043337 cardiolipin synthase (CMP-forming) activity | IMP PMID:9614098 Isolation and characterization of the gene (CLS1) encoding c... | ACCEPT | Summary: CLS1 disruption abolished CL synthase activity; overexpression and heterologous expression raised it. Supporting Evidence: PMID:9614098 Disruption of the CLS1 gene in a haploid yeast strain resulted in the loss of CL synthase activity, no detectable CL, a 5-fold elevation in phosphatidylglycerol levels PMID:9614098 Overexpression of the CLS1 gene under its endogenous promoter or the inducible GAL1 promoter in yeast and expression of CLS1 in baculovirus-infected insect cells resulted in elevated CL synthase activity. |
| GO:0043337 cardiolipin synthase (CMP-forming) activity | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (PHOS-PWY) to cardiolipin synthase (CMP-forming) activity. The GO term is correct for Crd1. Note, however, that the YeastPathways reaction for this step is written as 2 PG -> CL + glycerol (the bacterial PLD-type ClsA reaction); Crd1 uses CDP-DAG + PG and releases CMP, so the pathway reaction, not this GO term, is wrong. Supporting Evidence: PMID:2171667 Cardiolipin (CL) synthase activity was characterized in mitochondrial extracts of the yeast Saccharomyces cerevisiae and was shown for the first time to utilize CDP-diacylglycerol as a substrate. |
| GO:0043337 cardiolipin synthase (CMP-forming) activity | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (PHOSLIPSYN2-PWY-1) to cardiolipin synthase (CMP-forming) activity. The GO term is correct for Crd1. Note, however, that the YeastPathways reaction for this step is written as 2 PG -> CL + glycerol (the bacterial PLD-type ClsA reaction); Crd1 uses CDP-DAG + PG and releases CMP, so the pathway reaction, not this GO term, is wrong. Supporting Evidence: PMID:2171667 Cardiolipin (CL) synthase activity was characterized in mitochondrial extracts of the yeast Saccharomyces cerevisiae and was shown for the first time to utilize CDP-diacylglycerol as a substrate. |
| GO:0043337 cardiolipin synthase (CMP-forming) activity | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (PWY3O-2) to cardiolipin synthase (CMP-forming) activity. The GO term is correct for Crd1. Note, however, that the YeastPathways reaction for this step is written as 2 PG -> CL + glycerol (the bacterial PLD-type ClsA reaction); Crd1 uses CDP-DAG + PG and releases CMP, so the pathway reaction, not this GO term, is wrong. Supporting Evidence: PMID:2171667 Cardiolipin (CL) synthase activity was characterized in mitochondrial extracts of the yeast Saccharomyces cerevisiae and was shown for the first time to utilize CDP-diacylglycerol as a substrate. |
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Download this section (compressed HTML)Q: Which inner-membrane partners (e.g. Tam41, Pgs1, Gep4) form the reported large Crd1-containing complex, and is substrate channelling required for CL synthesis?
Q: Should YeastPathways correct the cardiolipin synthase reaction from 2 PG -> CL + glycerol to CDP-DAG + PG -> CL + CMP for S. cerevisiae?
Experiment: Native mass spectrometry or crosslinking-MS of the Crd1 complex in purified inner membranes to identify partners and test substrate channelling from Tam41/Gep4.
Cardiolipin synthase; produces cardiolipin, which is a phospholipid of the mitochondrial inner membrane that is required for normal mitochondrial membrane potential and function and for correct integration of membrane-multispanning proteins into the mitochondrial outer membrane; required to maintain tubular mitochondrial morphology and functions in mitochondrial fusion; also required for normal vacuolar ion homeostasis
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