PIMTEC=2.1.1.77 L-isoaspartyl protein carboxyl methyltransferase; Protein L-isoaspartyl/D-aspartyl methyltransferase; Protein-beta-aspartate methyltransferase;
Organism
Mus musculus (Mouse)
NCBI Taxonomy ID
10090
Chromosome Location
chr:10;7349171-7400934;-1
View in Ensembl genome browser
Function in Stage
Uncertain
Function in Cell Type
Uncertain
Probability (GAS) of Function in Spermatogenesis
0.621856392 The probability was calculated by GAS algorithm, ranging from 0 to 1. The closer it is to 1, the more possibly it functions in spermatogenesis.
Description
Temporarily unavailable
Abstract of related literatures
1. Two overlapping clones containing the entire 684-nucleotide (nt) sequence encoding murine protein beta-aspartate methyltransferase (EC 2.1.1.77) were isolated from a genomic library. Partial nt sequence analysis of the two clones revealed that the protein carboxyl methyltransferase (PCMT)-encoding sequence is distributed among seven exons, ranging from 32 to 339 bp in length, within 25 kb of genomic DNA. Three exons correspond to regions of primary structure which are strongly conserved among a number of eukaryotic and prokaryotic enzymes which utilize S-adenosylmethionine (AdoMet) and S-adenosylhomocysteine (AdoHcy). The 5'-flanking region of the PCMT-encoding gene (PCMT) contains an 800-bp G+C-rich region with potential binding sites for transcription factor ETF, but lacks a TATA box and binding sites for other known transcription factors. Multiple PCMT mRNAs were detected on Northern blots of RNA extracted from murine brain, testis, liver and kidney. The overall abundance of PCMT mRNAs in each tissue paralleled the measured specific activity of the PCMT. Comparison of the genomic sequence information with the 3'-untranslated regions (UTRs) of two cDNA clones from a murine testis library indicated that PCMT mRNA precursors undergo alternative splicing. The structure and widespread expression of PCMT are characteristics of vertebrate housekeeping genes. PMID: [1511895]
2. The National Institutes of Health's Mammalian Gene Collection (MGC) project was designed to generate and sequence a publicly accessible cDNA resource containing a complete open reading frame (ORF) for every human and mouse gene. The project initially used a random strategy to select clones from a large number of cDNA libraries from diverse tissues. Candidate clones were chosen based on 5'-EST sequences, and then fully sequenced to high accuracy and analyzed by algorithms developed for this project. Currently, more than 11,000 human and 10,000 mouse genes are represented in MGC by at least one clone with a full ORF. The random selection approach is now reaching a saturation point, and a transition to protocols targeted at the missing transcripts is now required to complete the mouse and human collections. Comparison of the sequence of the MGC clones to reference genome sequences reveals that most cDNA clones are of very high sequence quality, although it is likely that some cDNAs may carry missense variants as a consequence of experimental artifact, such as PCR, cloning, or reverse transcriptase errors. Recently, a rat cDNA component was added to the project, and ongoing frog (Xenopus) and zebrafish (Danio) cDNA projects were expanded to take advantage of the high-throughput MGC pipeline. PMID: [15489334]
3. The gene encoding the protein L-isoaspartyl-(D-aspartyl) methyltransferase (protein carboxyl methyltransferase, PCMT) is widely expressed in bacteria and eucaryotic cells. An antisense probe encompassing the first exon of the murine PCMT gene [E. A. Romanik, C. L. Ladino, S. C. D'Ardenne, and C. M. O'Connor (1992) Gene 118, 217-222] was used in ribonuclease protection assays to identify the initiation sites for PCMT transcription in mouse testis, brain, and liver tissues. Two major initiation sites, 155-157 nucleotides (nt) and 119 nt upstream from the ATG initiation codon, were identified in all tissues in addition to several minor sites. The locations of the initiation sites in testicular RNA were confirmed using ligation-mediated 5'-rapid amplification of cDNA ends (RACE). These initiation sites are situated at the 3'-end of a 407-bp genomic sequence which is sufficient to drive the expression of a firefly luciferase gene in transient transfection assays with NIH/3T3 cells. The 407-bp sequence resembles a housekeeping gene promoter in its high G+C content, lack of a TATA box and the presence of multiple potential binding sites for the transcription factors Sp1 and ETF. Alternative splicing in the C-terminal encoding sequence and in the 3'-untranslated regions of PCMT transcripts generates three distinct classes of mRNAs which were cloned from testicular poly(A)+ RNA using 3'-RACE. Transcript splicing either 38 nt downstream or 7 nt upstream from the termination codon in exon 7 produces mRNAs encoding PCMT isozymes with -RWK or -RDEL, respectively, at their C-termini. The predominant transcript in testis, which is not detected in somatic tissues by Northern blotting and which may be specific to germ cells, is not spliced within exon 7 and also encodes the -RWK isozyme. PMID: [8037467]
4. We report the use of a proteomic strategy to identify hitherto unknown substrates for mammalian protein l-isoaspartate O-methyltransferase. This methyltransferase initiates the repair of isoaspartyl residues in aged or stress-damaged proteins in vivo. Tissues from mice lacking the methyltransferase (Pcmt1(-/-)) accumulate more isoaspartyl residues than their wild-type littermates, with the most "damaged" residues arising in the brain. To identify the proteins containing these residues, brain homogenates from Pcmt1(-/-) mice were methylated by exogenous repair enzyme and the radiolabeled methyl donor S-adenosyl-[methyl-(3)H]methionine. Methylated proteins in the homogenates were resolved by both one-dimensional and two-dimensional electrophoresis, and methyltransferase substrates were identified by their increased radiolabeling when isolated from Pcmt1(-/-) animals compared with Pcmt1(+/+) littermates. Mass spectrometric analyses of these isolated brain proteins reveal for the first time that microtubule-associated protein-2, calreticulin, clathrin light chains a and b, ubiquitin carboxyl-terminal hydrolase L1, phosphatidylethanolamine-binding protein, stathmin, beta-synuclein, and alpha-synuclein, are all substrates for the l-isoaspartate methyltransferase in vivo. Our methodology for methyltransferase substrate identification was further supplemented by demonstrating that one of these methyltransferase targets, microtubule-associated protein-2, could be radiolabeled within Pcmt1(-/-) brain extracts using radioactive methyl donor and exogenous methyltransferase enzyme and then specifically immunoprecipitated with microtubule-associated protein-2 antibodies to recover co-localized protein with radioactivity. We comment on the functional significance of accumulation of relatively high levels of isoaspartate within these methyltransferase targets in the context of the histological and phenotypical changes associated with the methyltransferase knock-out mice. PMID: [16923807]
Catalyzes the methyl esterification of L-isoaspartyl andD-aspartyl residues in peptides and proteins that result fromspontaneous decomposition of normal L-aspartyl and L-asparaginylresidues. It plays a role in the repair and/or degradation ofdamaged proteins. Acts on microtubule-associated protein 2,calreticulin, clathrin light chains a and b, Ubiquitin carboxyl-terminal hydrolase isozyme L1, phosphatidylethanolamine-bindingprotein 1, stathmin, beta-synuclein and alpha-synuclein.