More Like this

1. Identification of lysine isobutyrylation as a new histone modification mark

   https://doi.org/10.1093/nar/gkaa1176  

   Zhu, Zhesi ; Han, Zhen ; Halabelian, Levon ; Yang, Xiangkun ; Ding, Jun ; Zhang, Nawei ; Ngo, Liza ; Song, Jiabao ; Zeng, Hong ; He, Maomao ; et al ( December 2020 , Nucleic Acids Research)

   null (Ed.)

   Abstract Short-chain acylations of lysine residues in eukaryotic proteins are recognized as essential posttranslational chemical modifications (PTMs) that regulate cellular processes from transcription, cell cycle, metabolism, to signal transduction. Lysine butyrylation was initially discovered as a normal straight chain butyrylation (Knbu). Here we report its structural isomer, branched chain butyrylation, i.e. lysine isobutyrylation (Kibu), existing as a new PTM on nuclear histones. Uniquely, isobutyryl-CoA is derived from valine catabolism and branched chain fatty acid oxidation which is distinct from the metabolism of n-butyryl-CoA. Several histone acetyltransferases were found to possess lysine isobutyryltransferase activity in vitro, especially p300 and HAT1. Transfection and western blot experiments showed that p300 regulated histone isobutyrylation levels in the cell. We resolved the X-ray crystal structures of HAT1 in complex with isobutyryl-CoA that gleaned an atomic level insight into HAT-catalyzed isobutyrylation. RNA-Seq profiling revealed that isobutyrate greatly affected the expression of genes associated with many pivotal biological pathways. Together, our findings identify Kibu as a novel chemical modification mark in histones and suggest its extensive role in regulating epigenetics and cellular physiology. 

   more » « less
2. Dynamic acylome reveals metabolite driven modifications in Syntrophomonas wolfei

   https://doi.org/10.3389/fmicb.2022.1018220  

   Fu, Janine Y. ; Muroski, John M. ; Arbing, Mark A. ; Salguero, Jessica A. ; Wofford, Neil Q. ; McInerney, Michael J. ; Gunsalus, Robert P. ; Loo, Joseph A. ; Ogorzalek Loo, Rachel R. ( November 2022 , Frontiers in Microbiology)

   Syntrophomonas wolfei is an anaerobic syntrophic microbe that degrades short-chain fatty acids to acetate, hydrogen, and/or formate. This thermodynamically unfavorable process proceeds through a series of reactive acyl-Coenzyme A species (RACS). In other prokaryotic and eukaryotic systems, the production of intrinsically reactive metabolites correlates with acyl-lysine modifications, which have been shown to play a significant role in metabolic processes. Analogous studies with syntrophic bacteria, however, are relatively unexplored and we hypothesized that highly abundant acylations could exist in S. wolfei proteins, corresponding to the RACS derived from degrading fatty acids. Here, by mass spectrometry-based proteomics (LC–MS/MS), we characterize and compare acylome profiles of two S. wolfei subspecies grown on different carbon substrates. Because modified S. wolfei proteins are sufficiently abundant to analyze post-translational modifications (PTMs) without antibody enrichment, we could identify types of acylations comprehensively, observing six types (acetyl-, butyryl-, 3- hydroxybutyryl-, crotonyl-, valeryl-, and hexanyl-lysine), two of which have not been reported in any system previously. All of the acyl-PTMs identified correspond directly to RACS in fatty acid degradation pathways. A total of 369 sites of modification were identified on 237 proteins. Structural studies and in vitro acylation assays of a heavily modified enzyme, acetyl-CoA transferase, provided insight on the potential impact of these acyl-protein modifications. The extensive changes in acylation-type, abundance, and modification sites with carbon substrate suggest that protein acylation by RACS may be an important regulator of syntrophy. 

   more » « less
3. DeepSuccinylSite: a deep learning based approach for protein succinylation site prediction.

   Niraj Thapa, Meenal Chaudhari ( April 2020 , BMC bioinformatics)

   Protein succinylation has recently emerged as an important and common post-translation modification (PTM) that occurs on lysine residues. Succinylation is notable both in its size (e.g., at 100 Da, it is one of the larger chemical PTMs) and in its ability to modify the net charge of the modified lysine residue from + 1 to − 1 at physiological pH. The gross local changes that occur in proteins upon succinylation have been shown to correspond with changes in gene activity and to be perturbed by defects in the citric acid cycle. These observations, together with the fact that succinate is generated as a metabolic intermediate during cellular respiration, have led to suggestions that protein succinylation may play a role in the interaction between cellular metabolism and important cellular functions. For instance, succinylation likely represents an important aspect of genomic regulation and repair and may have important consequences in the etiology of a number of disease states. In this study, we developed DeepSuccinylSite, a novel prediction tool that uses deep learning methodology along with embedding to identify succinylation sites in proteins based on their primary structure. 

   more » « less
4. Bioorthogonal Reporters for Detecting and Profiling Protein Acetylation and Acylation

   https://doi.org/10.1177/2472555219887144  

   Song, Jiabao ; Zheng, Y. George ( November 2019 , SLAS DISCOVERY: Advancing the Science of Drug Discovery)

   Protein acylation, exemplified by lysine acetylation, is a type of indispensable and widespread protein posttranslational modification in eukaryotes. Functional annotation of various lysine acetyltransferases (KATs) is critical to understanding their regulatory roles in abundant biological processes. Traditional radiometric and immunosorbent assays have found broad use in KAT study but have intrinsic limitations. Designing acyl–coenzyme A (CoA) reporter molecules bearing chemoselective chemical warhead groups as surrogates of the native cofactor acetyl-CoA for bioorthogonal labeling of KAT substrates has come into a technical innovation in recent years. This chemical biology platform equips molecular biologists with empowering tools in acyltransferase activity detection and substrate profiling. In the bioorthogonal labeling, protein substrates are first enzymatically modified with a functionalized acyl group. Subsequently, the chemical warhead on the acyl chain conjugates with either an imaging chromophore or an affinity handle or any other appropriate probes through an orthogonal chemical ligation. This bioorganic strategy reformats the chemically inert acetylation and acylation marks into a chemically maneuverable functionality and generates measurable signals without recourse to radioisotopes or antibodies. It offers ample opportunities for facile sensitive detection of KAT activity with temporal and spatial resolutions as well as allows for chemoproteomic profiling of protein acetylation pertaining to specific KATs of interest on the global scale. We reviewed here the past and current advances in bioorthogonal protein acylations and highlighted their wide-spectrum applications. We also discussed the design of other related acyl-CoA and CoA-based chemical probes and their deployment in illuminating protein acetylation and acylation biology.

    

   more » « less
5. The role of lysine acetylation in the function of mitochondrial ribosomal protein L12

   https://doi.org/10.1002/prot.26654  

   Paluch, Katelynn V. ; Platz, Karlie R. ; Rudisel, Emma J. ; Erdmann, Ryan R. ; Laurin, Taylor R. ; Dittenhafer‐Reed, Kristin E. ( December 2023 , Proteins: Structure, Function, and Bioinformatics)

   Mitochondria play a central role in energy production and cellular metabolism. Mitochondria contain their own small genome (mitochondrial DNA, mtDNA) that carries the genetic instructions for proteins required for ATP synthesis. The mitochondrial proteome, including the mitochondrial transcriptional machinery, is subject to post‐translational modifications (PTMs), including acetylation and phosphorylation. We set out to determine whether PTMs of proteins associated with mtDNA may provide a potential mechanism for the regulation of mitochondrial gene expression. Here, we focus on mitochondrial ribosomal protein L12 (MRPL12), which is thought to stabilize mitochondrial RNA polymerase (POLRMT) and promote transcription. Numerous acetylation sites of MRPL12 were identified by mass spectrometry. We employed amino acid mimics of the acetylated (lysine to glutamine mutants) and deacetylated (lysine to arginine mutants) versions of MRPL12 to interrogate the role of lysine acetylation in transcription initiation in vitro and mitochondrial gene expression in HeLa cells. MRPL12 acetyl and deacetyl protein mimics were purified and assessed for their ability to impact mtDNA promoter binding of POLRMT. We analyzed mtDNA content and mitochondrial transcript levels in HeLa cells upon overexpression of acetyl and deacetyl mimics of MRPL12. Our results suggest that MRPL12 single‐site acetyl mimics do not change the mtDNA promoter binding ability of POLRMT or mtDNA content in HeLa cells. Individual acetyl mimics may have modest effects on mitochondrial transcript levels. We found that the mitochondrial deacetylase, Sirtuin 3, is capable of deacetylating MRPL12 in vitro, suggesting a potential role for dynamic acetylation controlling MRPL12 function in a role outside of the regulation of gene expression.

    

   more » « less