scholarly journals The sequence of the major protein stored in ovine ceroid lipofuscinosis is identical with that of the dicyclohexylcarbodiimide-reactive proteolipid of mitochondrial ATP synthase

1990 ◽  
Vol 268 (3) ◽  
pp. 751-758 ◽  
Author(s):  
I M Fearnley ◽  
J E Walker ◽  
R D Martinus ◽  
R D Jolly ◽  
K B Kirkland ◽  
...  
Keyword(s):  
Amino Acid ◽  
Atp Synthase ◽  
Direct Analysis ◽  
Proteolytic Processing ◽  
Major Protein ◽  
Lysosomal Storage ◽  
Post Translational Modification ◽  
Mitochondrial Import ◽  
Mitochondrial Atp Synthase ◽  
C Subunit

The ceroid lipofuscinoses are a group of neurodegenerative lysosomal storage diseases of children and animals that are recessively inherited. In diseased individuals fluorescent storage bodies accumulate in a wide variety of cells, including neurons. Previous studies of these bodies isolated from tissues of affected sheep confirmed that the storage occurs in lysosomes, and showed that the storage body is mostly made of a single protein with an apparent molecular mass of 3500 Da with an N-terminal amino acid sequence that is the same as residues 1-40 of the c-subunit (or dicyclohexylcarbodi-imide-reactive proteolipid) of mitochondrial ATP synthase. In the present work we have shown by direct analysis that the stored protein is identical in sequence with the entire c-subunit of mitochondrial ATP synthase, a very hydrophobic protein of 75 amino acid residues. As far as can be detected by the Edman degradation, the stored protein appears not to have been subject to any post-translational modification other than the correct removal of the mitochondrial import sequences that have been shown in other experiments to be present at the N-terminal of its two different precursors. No other protein accumulates in the storage bodies to any significant extent. Taken with studies of the cDNAs for the c-subunit in normal and diseased sheep, these results indicate that the material that is stored in lysosomes of diseased animals has probably entered mitochondria and has been subjected to the proteolytic processing that is associated with mitochondrial import. This implies that the defect that leads to the lysosomal accumulation concerns the degradative pathway of the c-subunit of ATP synthase. An alternative, but less likely, hypothesis is that for some unknown reason the precursors of subunit c are being directly mis-targeted to lysosomes, where they become processed to yield a protein identical with the protein that is normally found in the mitochondrial ATP synthase assembly, and which then accumulates.

scholarly journals Characterization of the expressed genes for subunit c of mitochondrial ATP synthase in sheep with ceroid lipofuscinosis

1993 ◽  
Vol 293 (1) ◽  
pp. 65-73 ◽  
Author(s):  
S M Medd ◽  
J E Walker ◽  
R D Jolly
Keyword(s):  
Atp Synthase ◽  
Mitochondrial Targeting ◽  
Mitochondrial Import ◽  
Fragment Analysis ◽  
Subunit C ◽  
Ceroid Lipofuscinosis ◽  
Mitochondrial Atp Synthase ◽  
C Subunit ◽  
Healthy Control

The human and bovine genomes each contain two expressed nuclear genes, called P1 and P2, for subunit c, a hydrophobic subunit of the membrane sector, Fo, of mitochondrial ATP synthase. Both P1 and P2 encode the same mature protein, but the associated mitochondrial import sequences are different. In sheep with the neurodegenerative disease ceroid lipofuscinosis, and also in humans with Batten's disease, unmodified subunit c accumulates in lysosome-derived organelles in a variety of tissues. However, the sequences of cDNAs for P1 and P2 from sheep with ceroid lipofuscinosis were identical to those in healthy control animals. Therefore, since there was no mutation in either of the mitochondrial import sequences of subunit c in the diseased animals, ceroid lipofuscinosis does not arise from changes in an import sequence causing mis-targeting of the c subunit to lysosomes. The levels of expression of P1 and P2 genes were approximately the same in diseased and healthy animals, and so the protein is unlikely to accumulate because of excessive transcription of either gene. Transcription of a spliced pseudogene related to P2 was detected in both a control animal and a sheep with ceroid lipofuscinosis. The transcripts encode amino acids 1-31 of the P2 mitochondrial targeting sequence. In the diseased animal, an arginine replaced a glutamine in the control sequence. However, restriction fragment analysis of genomic DNA from a further 12 sheep established that the sequence differences were not linked to ceroid lipofuscinosis.

scholarly journals Chitin-binding proteins in potato (Solanum tuberosum L.) tuber. Characterization, immunolocalization and effects of wounding

1992 ◽  
Vol 283 (3) ◽  
pp. 813-821 ◽  
Author(s):  
D J Millar ◽  
A K Allen ◽  
C G Smith ◽  
C Sidebottom ◽  
A R Slabas ◽  
...  
Keyword(s):  
Solanum Tuberosum ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Binding Proteins ◽  
Solanum Tuberosum L ◽  
Major Protein ◽  
Post Translational Modification ◽  
Terminal Amino Acid ◽  
Terminal Amino ◽  
Terminal Amino Acid Sequence

Tubers of potato (Solanum tuberosum L.) contain a number of chitin-binding proteins which have possible functions in defence against pathogens. A major protein of the tuber is the chitin-binding lectin which has been further characterized with respect to its antigenicity and N-terminal amino acid sequence. By using an antiserum monospecific for tuber lectin in unwounded potato the protein was found in the cytoplasm and vacuole, unusually for a hydroxyproline-rich glycoprotein, but consistent with its soluble nature in subcellular extracts. Little increased synthesis of the lectin precursor or the post-translationally modified form could be demonstrated in excised potato tuber discs. However, after wounding there is increased synthesis of another hydroxyproline-containing glycoprotein of Mr 57,000, which binds to chitin and shares common epitopes with the lectin. In comparison with the tuber lectin, this novel glycoprotein contains less hydroxyproline, but from its overall composition it is clearly not an underhydroxylated form of the tuber lectin. It differed in its N-terminal amino acid sequence and was much less glycosylated, although arabinose was still present. Synthesis of the Mr-57,000 polypeptide began after the initial burst of protein synthesis and increased, reaching a peak at 24 h after wounding. The protein was produced with its enzymes of post-translational modification, prolyl hydroxylase and arabinosyltransferase, concomitantly with the marker enzymes for wounding, phenylalanine ammonia-lyase and membrane-bound phenol oxidase and peroxidase.

scholarly journals Lysosomal Storage of Subunit c of Mitochondrial ATP Synthase in Brain-Specific Atp13a2-Deficient Mice

2016 ◽  
Vol 186 (12) ◽  
pp. 3074-3082 ◽  
Author(s):  
Shigeto Sato ◽  
Masato Koike ◽  
Manabu Funayama ◽  
Junji Ezaki ◽  
Takahiro Fukuda ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Lysosomal Storage ◽  
Subunit C ◽  
Mitochondrial Atp Synthase ◽  
Deficient Mice

scholarly journals Sequences of members of the human gene family for the c subunit of mitochondrial ATP synthase

1993 ◽  
Vol 293 (1) ◽  
pp. 51-64 ◽  
Author(s):  
M R Dyer ◽  
J E Walker
Keyword(s):  
Human Genome ◽  
Atp Synthase ◽  
Dna Sequences ◽  
Human Gene ◽  
Membrane Component ◽  
Subunit C ◽  
Coding Sequences ◽  
Mitochondrial Atp Synthase ◽  
C Subunit ◽  
Potential Promoter

Subunit c is an intrinsic membrane component of ATP synthase, and in mammals it is encoded by two expressed nuclear genes, P1 and P2. Both genes encode the same mature c subunit, but the mitochondrial import pre-sequences in the precursors of subunit c are different. The DNA sequences of the human P1 and P2 genes are described. They occupy about 3.0 and 10.9 kb respectively of the human genome, and both genes are split into five exons. The human genome also contains about 14 related spliced pseudogenes, and the sequence of one such pseudogene related to P2 is described. Sequences flanking the 5′ ends of the human P1 and P2 coding sequences each contain a CpG-rich island. Potential promoter elements (TATA and CCAAT boxes) are present in the 5′ sequences of the P1 gene, but not that of P2, although there is no direct experimental evidence to show the involvement of these sequences in transcription of the genes.

scholarly journals Heterogeneity in Proline Hydroxylation of Fibrillar Collagens Observed by Mass Spectrometry

2021 ◽  
Author(s):  
Michele Kirchner ◽  
Haiteng Deng ◽  
Yujia Xu
Keyword(s):  
Mass Spectrometry ◽  
Amino Acid ◽  
Type I Collagen ◽  
Single Letter ◽  
Major Protein ◽  
Type I ◽  
Post Translational Modification ◽  
Functional Roles ◽  
Commercial Sources ◽  
And Function

AbstractCollagen is the major protein in the extracellular matrix and plays vital roles in tissue development and function. Collagen is also one of the most processed proteins in its biosynthesis. The most prominent post-translational modification (PTM) of collagen is the hydroxylation of Pro residues in the Y-position of the characteristic (Gly-Xaa-Yaa) repeating amino acid sequence of a collagen triple helix. Recent studies using mass-spectrometry (MS) and tandem MS sequencing (MS/MS) have revealed unexpected hydroxylation of Pro residues in the X-positions (X-Hyp). The newly identified X-Hyp residues appear to be highly heterogeneous in location and percent occupancy. In order to understand the dynamic nature of the new X-Hyps and their potential impact on applications of MS and MS/MS for collagen research, we sampled four different collagen samples using standard MS and MS/MS techniques. We found considerable variations in the degree of PTMs of the same collagen from different organisms and/or tissues. The rat tail tendon type I collagen is particularly variable in terms of both over-hydroxylation of Pro in the X-position and under-hydroxylation of Pro in the Y-position. In contrast, only a few unexpected PTMs in collagens type I and type III from human placenta were observed. The reproducibility of the different sequencing efforts of the same sample is also limited especially when the modified species are present at a low population, presumably due to the unpredictable nature of the ionization process. Additionally, despite the heterogeneous preparation and sourcing, collagen samples from commercial sources do not show elevated variations in PTMs compared to samples prepared from a single tissue and/or organism. These findings will contribute to the growing body of information regarding the PTMs of collagen by MS technology, and culminate to a more comprehensive understanding of the extent and the functional roles of the PTMs of collagen.Abbreviations pageBoth the single letter and the three letter abbreviations of an amino acid will be used with the following additions: Hyp or O stands for 4R-hydroxylated proline and 3Hyp stands for 3- hydroxylated proline. When needed for clarity, the lower case single letter abbreviation will be used to represent the genomic DNA sequence, and upper case ones the sequence seen in the peptides.

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