Latency-associated Peptide of Transforming Growth Factor-β1 Is Not Subject to Physiological Mannose Phosphorylation

Barnes, Jarrod W.; Warejcka, Debra J.; Simpliciano, Jennifer; Twining, Sally S.; Steet, Richard

doi:10.1074/jbc.m111.308825

Cited by 10 publications

(11 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Human erythroleukemia (HEL) cells grown in suspension can be differentiated to adherent megakaryocytes by phorbol 12-myristate 13-acetate (PMA) treatment, providing an opportunity to analyze how the profile of sialoglycoproteins changes upon differentiation with various labeling methods (13)(14)(15). Metabolic labeling of HEL cells with Ac 4 ManNAz showed predominantly O-sialoglycoproteins being labeled as demonstrated by the insensitivity of labeled glycoproteins to PNGase F treatment (Fig.…”

Section: Resultsmentioning

confidence: 99%

Selective Exo-Enzymatic Labeling Detects Increased Cell Surface Sialoglycoprotein Expression upon Megakaryocytic Differentiation

Yu¹,

Zhao²,

Sun

et al. 2016

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Selective exo-enzymatic labeling (or SEEL) uses recombinant glycosyltransferases and nucleotide-sugar analogues to allow efficient labeling of cell surface glycans. SEEL can circumvent many of the possible issues associated with metabolic labeling, including low incorporation of sugar precursors, and allows for sugars to be added selectively to different types of glycans by virtue of the inherent specificity of the glycosyltransferases. Here we compare the labeling of sialoglycoproteins in undifferentiated and differentiated human erythroleukemia cells (HEL) using SEEL using the sialyltransferases ST6Gal1 and ST3Gal1, which label N-and O-glycans, respectively. Our results show that the profile of glycoproteins detected varies between undifferentiated HEL cells and those differentiated to megakaryocytes, with a shift to more N-linked sialoglycoproteins in the differentiated cells. The efficiency of SEEL for both sialyltransferases in HEL cells was greatly increased with prior neuraminidase treatment highlighting the necessity for the presence of available acceptors with this labeling method. Following metabolic labeling or SEEL, tagged glycoproteins were enriched by immunoprecipitation and identified using mass spectrometry. The proteomic findings demonstrated that the detection of many glycoproteins is markedly improved by SEEL labeling, and that unique glycoproteins can be identified using either ST6Gal1 or ST3Gal1. Furthermore, this analysis enabled the identification of increased surface expression of several sialylated cell adhesion molecules, including the known megakaryocytic markers integrin␤3 and CD44, upon differentiation of HEL cells to adherent megakaryocytes.The ability to label glycans using chemical glycobiology methods has ushered in new opportunities to investigate the functions of these molecules in living systems (1-3). These studies are beginning to yield insight into how glycan profiles changes during development and how the content, localization, and trafficking of glycans is altered in the context of many human diseases (4 -9). Most methodologies utilize metabolic labeling as a way to incorporate functionalized sugars into glycans during biosynthesis. The extent of labeling in some cell types may be limited by the presence of endogenous non-labeled sugar precursors that can dilute out the azide-sugars available for incorporation. Variable distribution of azide-sugars into different glycan classes (e.g. glycoproteins versus glycolipids) following metabolic labeling can also skew or limit the types of glycans that can be analyzed. As an alternative approach, labeling methods have been developed that instead rely on the use of recombinant or purified glycosyltransferases to install functionalized sugars directly onto existing glycans (10 -12). This method, recently termed SEEL (selective exoenzymatic labeling), 4 leverages the inherent selectivity of the recombinant glycosyltransferases to label certain types (e.g. N-linked or O-linked) of glycans. Prior work using the sialyltransferase ST6Gal...

show abstract

Section: Resultsmentioning

confidence: 99%

Selective Exo-Enzymatic Labeling Detects Increased Cell Surface Sialoglycoprotein Expression upon Megakaryocytic Differentiation

Yu¹,

Zhao²,

Sun

et al. 2016

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

show abstract

“…Transient transfection and latent TGFβ1 secretion assays-HeLa cells were transfected with latent TGFβ1, glycopepsinogen, and/or sortilin-1 in Opti-MEM using Lipofectamine PLUS reagents as previously described [52]. In all co-transfection experiments, 2.5 µg of sortilin-1 and 0.3 µg of latent TGFβ1 or glycopepsinogen DNA were used.…”

Section: Preparation Of Sds Whole Cell Lysates Doc (Deoxycholate)-somentioning

confidence: 99%

“…Thus, loss of this modification could directly inhibit activation. This idea has, however, been challenged by the demonstration that latent TGFβ1 is very poorly modified with Man-6-P under physiological conditions [52].…”

Section: Introductionmentioning

confidence: 99%

Upregulation of Sortilin, a Lysosomal Sorting Receptor, Corresponds with Reduced Bioavailability of Latent TGFβ in Mucolipidosis II Cells

et al. 2020

Self Cite

View full text Add to dashboard Cite

Mucolipidosis II (ML-II) is a lysosomal disease caused by defects in the carbohydrate-dependent sorting of soluble hydrolases to lysosomes. Altered growth factor signaling has been identified as a contributor to the phenotypes associated with ML-II and other lysosomal disorders but an understanding of how these signaling pathways are affected is still emerging. Here, we investigated transforming growth factor beta 1 (TGFβ1) signaling in the context of ML-II patient fibroblasts, observing decreased TGFβ1 signaling that was accompanied by impaired TGFβ1-dependent wound closure. We found increased intracellular latent TGFβ1 complexes, caused by reduced secretion and stable localization in detergent-resistant lysosomes. Sortilin, a sorting receptor for hydrolases and TGFβ-related cytokines, was upregulated in ML-II fibroblasts as well as GNPTAB-null HeLa cells, suggesting a mechanism for inappropriate lysosomal targeting of TGFβ. Co-expression of sortilin and TGFβ in HeLa cells resulted in reduced TGFβ1 secretion. Elevated sortilin levels correlated with normal levels of cathepsin D in ML-II cells, consistent with a compensatory role for this receptor in lysosomal hydrolase targeting. Collectively, these data support a model whereby sortilin upregulation in cells with lysosomal storage maintains hydrolase sorting but suppresses TGFβ1 secretion through increased lysosomal delivery. These findings highlight an unexpected link between impaired lysosomal sorting and altered growth factor bioavailability.

show abstract

“…Lines of evidences were based on purification of latent TGFβ from platelets or plasma, overexpression of proTGFβ1 with or without furin [Dubois et al, ], and conditional deletion of furin from T cells [Pesu et al, ]. An earlier investigation reported the presence of mannose‐6‐phospates on a recombinant TGFβ precursor [Purchio et al, ], but a later study dismissed such a presence [Barnes et al, ]. Currently, there are two models of furin cleavage of pro‐TGFβ: one requires a fusion of furin‐containing endosomes with constitutive secretory vesicles [Robertson et al, ], whereas the other requires extracellular furin or integrin activities [Constam, ; Travis and Sheppard, ].…”

Section: Discussionmentioning

confidence: 99%

HK2 Proximal Tubule Epithelial Cells Synthesize and Secrete Plasma Proteins Predominantly Through the Apical Surface

Zhao

Murray

2016

J of Cellular Biochemistry

View full text Add to dashboard Cite

Renal proximal tubule epithelial cells (PTECs) are known to reabsorb salts and small plasma proteins filtered through Bowman's capsule. Following acute kidney injury, PTECs assume some characteristics of hepatocytes in producing various plasma proteins. We now demonstrate that even at a resting state, a PTEC cell line, HK2 expresses mRNAs for and synthesizes and secretes plasma proteins in a complex with complement C3, an α -macroglobulin family chaperone, including albumin, transferrin, α -antitrypsin, α -antichymotrypsin, α -HS-glycoprotein, ceruloplasmin, haptoglobin, C1-inhibitor, secreted phosphoprotein-24, and insulin-like growth factor-1. When grown on transwell inserts, HK2 cells predominantly secrete (∼90%) plasma proteins into the apical side and a smaller fraction into the basolateral side as determined by ELISA assays. When cultured in the presence of exogenous cytokines such as IL1β, IL6, TNFα, BMP2, or TGFβ1, HK2 cell mRNA expressions for plasma proteins were variably affected whereas basolateral secretions were elevated to or in excess of those of the apical level. In addition, HK2 cells produce proTGFβ1 with its intact N-terminal latency associated peptide and latent-TGF-β-binding proteins. The complex cannot be dissociated under conditions of SDS, heating, and electrophoresis. Moreover, HK2 cells maintain their ability to quickly uptake exogenously added serum proteins from the culture medium, as if they are recognized differently by the endocytic receptors. These results provide new insight into the hepatization of PTECs. In addition to their unique uptake of plasma proteins and salts from the filtrate, they are a source of urinary proteins under normal conditions as wells as in chronic and acute kidney diseases. J. Cell. Biochem. 118: 924-933, 2017. © 2016 Wiley Periodicals, Inc.

show abstract

Latency-associated Peptide of Transforming Growth Factor-β1 Is Not Subject to Physiological Mannose Phosphorylation

Cited by 10 publications

References 44 publications

Selective Exo-Enzymatic Labeling Detects Increased Cell Surface Sialoglycoprotein Expression upon Megakaryocytic Differentiation

Selective Exo-Enzymatic Labeling Detects Increased Cell Surface Sialoglycoprotein Expression upon Megakaryocytic Differentiation

Upregulation of Sortilin, a Lysosomal Sorting Receptor, Corresponds with Reduced Bioavailability of Latent TGFβ in Mucolipidosis II Cells

HK2 Proximal Tubule Epithelial Cells Synthesize and Secrete Plasma Proteins Predominantly Through the Apical Surface

Contact Info

Product

Resources

About