RNA editing changes the sequence of many transcripts in plant organelles, but little is known about the molecular mechanisms determining the specificity of the process. In this study, we have characterized CLB19 (also known as PDE247), a gene that is required for editing of two distinct chloroplast transcripts, rpoA and clpP. Loss-of-function clb19 mutants present a yellow phenotype with impaired chloroplast development and early seedling lethality under greenhouse conditions. Transcript patterns are profoundly affected in the mutant plants, with a pattern entirely consistent with a defect in activity of the plastid-encoded RNA polymerase. CLB19 encodes a pentatricopeptide repeat protein similar to the editing specificity factors CRR4 and CRR21, but, unlike them, is implicated in editing of two target sites.
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http://dx.doi.org/10.1111/j.1365-313X.2008.03634.x | DOI Listing |
Biochemistry
December 2024
Department of Chemistry and Biochemistry, California State University Los Angeles, Los Angeles, California 90032, United States.
Plants make pyrimidine base substitutions in organellar mRNAs through the action of sequence-specific nuclear-encoded enzymes. Pentatricopeptide repeat (PPR) proteins are essential for ensuring specificity, while the enzymatic DYW domain is often present at the C-terminus of a PPR protein and dependent on the variant possessing C-to-U and/or U-to-C RNA editing activities. Expression of exogenous DYW-KP variant enzymes in bacteria leads to the modification of RNAs suggestive of U-to-C base changes.
View Article and Find Full Text PDFPlant Commun
December 2024
Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao 266237, China. Electronic address:
Pentatricopeptide repeat (PPR) proteins are involved in nearly all aspects of post-transcriptional processing in plant mitochondria and plastids, where they play a vital role in plant growth, development, cytoplasmic male sterility (CMS) restoration, and response to biotic and abiotic stresses. Through research in the last three decades, PPR functions and the primary mechanisms by which PPR proteins mediate post-transcriptional processing have been uncovered. Here, we aim to summarize the advances in PPR research with highlighting on the mechanisms of how PPR proteins mediate RNA editing, intron splicing, and RNA maturation in the context of their role in organellar gene expression.
View Article and Find Full Text PDFCell Signal
December 2024
Department of Nephrology, Jiading District Central Hospital Affiliated Shanghai University of Medicine & Health Sciences, Shanghai 201800, China. Electronic address:
Background: Methyltransferase-like protein 3 (METTL3) has been confirmed to act as a tumor promoter to regulate hepatocellular carcinoma (HCC) progression. Therefore, more roles and mechanisms of METTL3 in HCC progression deserve to be further revealed.
Methods: The mRNA and protein levels of METTL3, sphingomyelin phodiesterase acid-like 3 A (SMPDL3A), and leucine rich pentatricopeptide repeat containing (LRPPRC) were determined by qRT-PCR and western blot.
Breast cancer (BC) is among the most prevalent malignant cancers in women. We examined the function and regulatory mechanism of the N6-methyladenosine (m6A) modification reader leucine-rich pentatricopeptide repeat containing (LRPPRC) in BC inflammation and progression. LRPPRC and C-X-C motif chemokine ligand 11 (CXCL11) levels were measured by quantitative real-time polymerase chain reaction.
View Article and Find Full Text PDFPlant Cell Rep
November 2024
Center for Photosynthesis and Plant Stress Biology, College of Life Sciences, South-China Agricultural University, Guangzhou, 510642, China.
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