scholarly journals Lysine post-translational modifications of collagen

2012 ◽  
Vol 52 ◽  
pp. 113-133 ◽  
Author(s):  
Mitsuo Yamauchi ◽  
Marnisa Sricholpech

Type I collagen is the most abundant structural protein in vertebrates. It is a heterotrimeric molecule composed of two α1 chains and one α2 chain, forming a long uninterrupted triple helical structure with short non-triple helical telopeptides at both the N- and C-termini. During biosynthesis, collagen acquires a number of post-translational modifications, including lysine modifications, that are critical to the structure and biological functions of this protein. Lysine modifications of collagen are highly complicated sequential processes catalysed by several groups of enzymes leading to the final step of biosynthesis, covalent intermolecular cross-linking. In the cell, specific lysine residues are hydroxylated to form hydroxylysine. Then specific hydroxylysine residues located in the helical domain of the molecule are glycosylated by the addition of galactose or glucose-galactose. Outside the cell, lysine and hydroxylysine residues in the N- and C-telopeptides can be oxidatively deaminated to produce reactive aldehydes that undergo a series of non-enzymatic condensation reactions to form covalent intra- and inter-molecular cross-links. Owing to the recent advances in molecular and cellular biology, and analytical technologies, the biological significance and molecular mechanisms of these modifications have been gradually elucidated. This chapter provides an overview on these enzymatic lysine modifications and subsequent cross-linking.

2021 ◽  
Author(s):  
David M Hudson ◽  
Marilyn Archer ◽  
Jyoti Rai ◽  
MaryAnn Weis ◽  
Russell Fernandes ◽  
...  

Tendons and ligaments tend to be pooled into a single category as dense elastic bands of collagenous connective tissue. They do have many similar properties, for example both tissues are flexible cords of fibrous tissue that join bone to either muscle or bone. Tendons and ligaments are both prone to degenerate and rupture with only limited capacity to heal, however; healing outcomes for tendons are often faster than ligament injuries. Type I collagen constitutes about 80% of the dry weight of tendons and ligaments and is principally responsible for the core strength of each tissue. Collagen synthesis is a complex process with multiple steps and numerous post-translational modifications including proline and lysine hydroxylation, hydroxylysine glycosylation and covalent cross-linking. The chemistry, placement and quantity of intramolecular and intermolecular cross-links are believed to be key contributors to the tissue-specific variations in material strength and biological properties of collagens. As tendons and ligaments grow and develop, the collagen cross-links are known to chemically mature, strengthen and change in profile. Accordingly, changes in cross-linking and other post-translational modifications are likely associated with tissue development and degeneration. Using mass spectrometry, we have compared tendon and ligaments from fetal and adult bovine knee joints to investigate changes in collagen post-translational properties. Although hydroxylation levels at the type I collagen helical cross-linking lysine residues were similar in all adult tissues, ligaments had significantly higher levels of glycosylation at these sites compared to tendon. Differences in lysine hydroxylation were also found between the tissues at the telopeptide cross-linking sites. Total collagen cross-linking analysis, including mature trivalent cross-links and immature divalent cross-links, revealed unique cross-linking profiles between tendon and ligament tissues. Tendons were found to have a significantly higher frequency of smaller diameter collagen fibrils compared with ligament, which we propose is a consequence of the unique cross-linking profile of each tissue. Understanding the specific molecular characteristics that define and distinguish these specialized tissues will be important for designing improved orthopedic treatment approaches.


1982 ◽  
Vol 101 (2) ◽  
pp. 312-320 ◽  
Author(s):  
Hans Oxlund ◽  
Trevor Sims ◽  
Nicholas D. Light

Abstract. The effects of systemic cortisol treatment on the biophysical and biochemical properties of skin were investigated. Rats were injected sc with cortisol for 14, 60 and 120 days and samples of lumbar skin were studied. Corticosteroids exert a biphasic effect on the strength of skin: 1) a relatively fast increase in the strength and stability, caused by an increased collagen cross-linking and 2) an inhibited collagen synthesis which ultimately results in a thinning of the skin and a decrease of collagen content consistent with clinical observations. The thermal stability is increased indicating an increased proportion of thermostable cross-links in skin collagen. No changes are observed in the percentage type III collagen with respect to type I collagen. Increased amounts of glucose attached to the ε-amino group of lysine residues in the collagen are found after long-term treatments, an alteration which may play a role in hampering the tissue functions.


2013 ◽  
Vol 66 (7) ◽  
pp. 760 ◽  
Author(s):  
Irina Perdivara ◽  
Mitsuo Yamauchi ◽  
Kenneth B. Tomer

The most abundant proteins in vertebrates – the collagen family proteins – play structural and biological roles in the body. The predominant member, type I collagen, provides tissues and organs with structure and connectivity. This protein has several unique post-translational modifications that take place intra- and extra-cellularly. With growing evidence of the relevance of such post-translational modifications in health and disease, the biological significance of O-linked collagen glycosylation has recently drawn increased attention. However, several aspects of this unique modification – the requirement for prior lysyl hydroxylation as a substrate, involvement of at least two distinct glycosyl transferases, its involvement in intermolecular crosslinking – have made its molecular mapping and quantitative characterization challenging. Such characterization is obviously crucial for understanding its biological significance. Recent progress in mass spectrometry has provided an unprecedented opportunity for this type of analysis. This review summarizes recent advances in the area of O-glycosylation of fibrillar collagens and their characterization using state-of-the-art liquid chromatography–mass spectrometry-based methodologies, and perspectives on future research. The analytical characterization of collagen crosslinking and advanced glycation end-products are not addressed here.


1976 ◽  
Vol 153 (2) ◽  
pp. 211-215 ◽  
Author(s):  
A J Bailey ◽  
T J Sims

Both the type I and type III collagens present in embryonic dermis are stabilized by the intermolecular cross-link, hydroxylysino-5-oxonorleucine, derived from hydroxylysine-aldehyde, although the type I collagen possesses a significant proportion of dehydrohydroxylysinonorleucine. However, concurrent with the change in the proportion of the two types of collagen during postnatal development there is a change-over with both type I and III collagens to the labile cross-link, dehydrohydroxylysinonorleucine, derived from lysine aldehyde. The results indicate that the change in the nature of the cross-link with development is determined primarily by the change in the extent of hydroxylation of the lysine residues in the terminal non-helical regions rather than being due to the change in the type of collagen.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Masahiko Terajima ◽  
Yuki Taga ◽  
Becky K. Brisson ◽  
Amy C. Durham ◽  
Kotaro Sato ◽  
...  

AbstractIn spite of major advances over the past several decades in diagnosis and treatment, breast cancer remains a global cause of morbidity and premature death for both human and veterinary patients. Due to multiple shared clinicopathological features, dogs provide an excellent model of human breast cancer, thus, a comparative oncology approach may advance our understanding of breast cancer biology and improve patient outcomes. Despite an increasing awareness of the critical role of fibrillar collagens in breast cancer biology, tumor-permissive collagen features are still ill-defined. Here, we characterize the molecular and morphological phenotypes of type I collagen in canine mammary gland tumors. Canine mammary carcinoma samples contained longer collagen fibers as well as a greater population of wider fibers compared to non-neoplastic and adenoma samples. Furthermore, the total number of collagen cross-links enriched in the stable hydroxylysine-aldehyde derived cross-links was significantly increased in neoplastic mammary gland samples compared to non-neoplastic mammary gland tissue. The mass spectrometric analyses of type I collagen revealed that in malignant mammary tumor samples, lysine residues, in particular those in the telopeptides, were markedly over-hydroxylated in comparison to non-neoplastic mammary tissue. The extent of glycosylation of hydroxylysine residues was comparable among the groups. Consistent with these data, expression levels of genes encoding lysyl hydroxylase 2 (LH2) and its molecular chaperone FK506-binding protein 65 were both significantly increased in neoplastic samples. These alterations likely lead to an increase in the LH2-mediated stable collagen cross-links in mammary carcinoma that may promote tumor cell metastasis in these patients.


2021 ◽  
Vol 22 (4) ◽  
pp. 1861
Author(s):  
Jemima Seidenberg ◽  
Mara Stellato ◽  
Amela Hukara ◽  
Burkhard Ludewig ◽  
Karin Klingel ◽  
...  

Background: Pathological activation of cardiac fibroblasts is a key step in development and progression of cardiac fibrosis and heart failure. This process has been associated with enhanced autophagocytosis, but molecular mechanisms remain largely unknown. Methods and Results: Immunohistochemical analysis of endomyocardial biopsies showed increased activation of autophagy in fibrotic hearts of patients with inflammatory cardiomyopathy. In vitro experiments using mouse and human cardiac fibroblasts confirmed that blockade of autophagy with Bafilomycin A1 inhibited fibroblast-to-myofibroblast transition induced by transforming growth factor (TGF)-β. Next, we observed that cardiac fibroblasts obtained from mice overexpressing transcription factor Fos-related antigen 2 (Fosl-2tg) expressed elevated protein levels of autophagy markers: the lipid modified form of microtubule-associated protein 1A/1B-light chain 3B (LC3BII), Beclin-1 and autophagy related 5 (Atg5). In complementary experiments, silencing of Fosl-2 with antisense GapmeR oligonucleotides suppressed production of type I collagen, myofibroblast marker alpha smooth muscle actin and autophagy marker Beclin-1 in cardiac fibroblasts. On the other hand, silencing of either LC3B or Beclin-1 reduced Fosl-2 levels in TGF-β-activated, but not in unstimulated cells. Using a cardiac hypertrophy model induced by continuous infusion of angiotensin II with osmotic minipumps, we confirmed that mice lacking either Fosl-2 (Ccl19CreFosl2flox/flox) or Atg5 (Ccl19CreAtg5flox/flox) in stromal cells were protected from cardiac fibrosis. Conclusion: Our findings demonstrate that Fosl-2 regulates autophagocytosis and the TGF-β-Fosl-2-autophagy axis controls differentiation of cardiac fibroblasts. These data provide a new insight for the development of pharmaceutical targets in cardiac fibrosis.


1988 ◽  
Vol 255 (3) ◽  
pp. 869-876 ◽  
Author(s):  
D J Steenkamp

The mitochondrial electron-transfer flavoprotein (ETF) is a heterodimer containing only one FAD. In previous work on the structure-function relationships of ETF, its interaction with the general acyl-CoA dehydrogenase (GAD) was studied by chemical cross-linking with heterobifunctional reagents [D. J. Steenkamp (1987) Biochem. J. 243, 519-524]. GAD whose lysine residues were substituted with 3-(2-pyridyldithio)propionyl groups was preferentially cross-linked to the small subunit of ETF, the lysine residues of which had been substituted with 4-mercaptobutyramidine (MBA) groups. This work was extended to the interaction of ETF with ETF-ubiquinone oxidoreductase (ETF-Q ox). ETF-Q ox was partially inactivated by modification with N-succinimidyl 3-(2-pyridyldithio)propionate to introduce pyridyl disulphide structures. A similar modification of ETF caused a large increase in the apparent Michaelis constant of ETF-Q ox for modified ETF owing to the loss of positive charge on some critical lysines of ETF. When ETF-Q ox was modified with 2-iminothiolane to introduce 4-mercaptobutyramidine groups, only a minor effect on the activity of the enzyme was observed. To retain the positive charges on the lysine residues of ETF, pyridyl disulphide structures were introduced by treating ETF with 2-iminothiolane in the presence of 2,2′-dithiodipyridyl. The electron-transfer activity of the resultant ETF preparation containing 4-(2-pyridyldithio)butyramidine (PDBA) groups was only slightly affected. When ETF-Q ox substituted with MBA groups was mixed with ETF bearing PDBA groups, at least 70% of the cross-links formed between the two proteins were between the small subunit of ETF and ETF-Q ox. ETF-Q ox, therefore, interacts predominantly with the same subunit of ETF as GAD. Variables which affect the selectivity of ETF-Q ox cross-linking to the subunits of ETF are considered.


2009 ◽  
Vol 185 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Farideh Sabeh ◽  
Ryoko Shimizu-Hirota ◽  
Stephen J. Weiss

Tissue invasion during metastasis requires cancer cells to negotiate a stromal environment dominated by cross-linked networks of type I collagen. Although cancer cells are known to use proteinases to sever collagen networks and thus ease their passage through these barriers, migration across extracellular matrices has also been reported to occur by protease-independent mechanisms, whereby cells squeeze through collagen-lined pores by adopting an ameboid phenotype. We investigate these alternate models of motility here and demonstrate that cancer cells have an absolute requirement for the membrane-anchored metalloproteinase MT1-MMP for invasion, and that protease-independent mechanisms of cell migration are only plausible when the collagen network is devoid of the covalent cross-links that characterize normal tissues.


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