Binding of LARP6 to the Conserved 5′ Stem–Loop Regulates Translation of mRNAs Encoding Type I Collagen

Arterial stiffening, a characteristic feature of obesity and type 2 diabetes, contributes to the development and progression of cardiovascular diseases (CVD). Currently, no effective prophylaxis or therapeutics is available to prevent or treat arterial stiffening. A better understanding of the molecular mechanisms underlying arterial stiffening is vital to identify newer targets and strategies to reduce CVD burden. A major contributor to arterial stiffening is increased collagen deposition. In the 5' untranslated regions of mRNAs encoding for type I collagen, an evolutionally conserved stem-loop (SL) structure plays an essential role in its stability and post-transcriptional regulation. Here, we show that feeding a high fat/high sucrose (HFHS) diet for 28 weeks increases adiposity, insulin resistance, and blood pressure in male wild-type littermates. Moreover, arterial stiffness, assessed in vivo via aortic pulse wave velocity, and ex vivo using atomic force microscopy in aortic explants or pressure myography in isolated femoral and mesenteric arteries, was also increased in those mice. Notably, all these indices of arterial stiffness, along with collagen type I levels in the vasculature, were reduced in HFHS-fed mice harboring a mutation in the 5'SL structure, relative to wild-type littermates. This protective vascular phenotype in 5'SL-mutant mice did not associate with a reduction in insulin resistance or blood pressure. These findings implicate the 5'SL structure as a putative therapeutic target to prevent or reverse arterial stiffening and CVD associated with obesity and type 2 diabetes.

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Characterization of Sequence-Specific Binding of LARP6 to the 5’ Stem-Loop of Type I Collagen mRNAs and Implications for Rational Design of Antifibrotic Drugs

Journal of Molecular Biology ◽

10.1016/j.jmb.2021.167394 ◽

2021 ◽

pp. 167394

Author(s):

Lela Stefanovic ◽

Blaine H. Gordon ◽

Robert Silvers ◽

Branko Stefanovic

Keyword(s):

Rational Design ◽

Type I Collagen ◽

Specific Binding ◽

Type I ◽

Stem Loop ◽

Antifibrotic Drugs

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Characterization of binding of LARP6 to the 5’ stem-loop of collagen mRNAs: Implications for synthesis of type I collagen

RNA Biology ◽

10.1080/15476286.2014.996467 ◽

2014 ◽

Vol 11 (11) ◽

pp. 1386-1401 ◽

Cited By ~ 18

Author(s):

Lela Stefanovic ◽

Liam Longo ◽

Yujie Zhang ◽

Branko Stefanovic

Keyword(s):

Type I Collagen ◽

Type I ◽

Stem Loop

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Characterization of sequence specific binding of LARP6 to the 5’ stem-loop of type I collagen mRNAs and implications for rational design of antifibrotic drugs

10.1101/2020.09.30.320564 ◽

2020 ◽

Author(s):

Lela Stefanovic ◽

Blaine H. Gordon ◽

Robert Silvers ◽

Branko Stefanovic

Keyword(s):

Rational Design ◽

Type I Collagen ◽

Specific Binding ◽

High Rate ◽

Stable Complex ◽

Type I ◽

Stem Loop ◽

Rrm Domain ◽

Α Helix ◽

Antifibrotic Drugs

AbstractExcessive synthesis of type I collagen characterizes fibrotic diseases. Binding of LARP6 to the 5’ stem-loop (5’SL) of collagen mRNAs regulates their translation and the high rate of biosynthesis in fibrosis. LARP6 needs two domains to form stable complex with 5’SL RNA, the La-domain and the juxtaposed RRM domain (jointly called the La-module). We describe that the La-domain of LARP6 is necessary and sufficient for recognition of 5’SL in sequence specific manner. The three amino acid motif, RNK, located in the flexible loop which connects the second α-helix to the β-sheet of the La domain is critical for binding. Mutation of any of these three amino acids abolishes the binding of La-domain to 5’SL. The major site of crosslinking of LARP6 to 5’SL RNA was mapped to this motif. The RNK motif is not found in other LARPs, which can not bind 5’SL. Presence of RRM increases the stability of complex between La-domain and 5’SL RNA and RRM domain does not make extensive contacts with 5’SL RNA. We propose a model in which the initial recognition of 5’SL by LARP6 is mediated by the RNK epitope and further stabilized by the RRM domain. This discovery suggests that the interaction between LARP6 and collagen mRNAs can be blocked by small molecules that target the RNK epitope and will help rational design of the LARP6 binding inhibitors as specific antifibrotic drugs.

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Collagen fibrillogenesis in vitro: interaction of types I and V collagen

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100142670 ◽

1986 ◽

Vol 44 ◽

pp. 210-211

Author(s):

Arthur J. Wasserman ◽

Kathy C. Kloos ◽

David E. Birk

Keyword(s):

Type I Collagen ◽

Corneal Stroma ◽

Minor Component ◽

Homogeneous Distribution ◽

Type I ◽

Type V Collagen ◽

Fibril Morphology ◽

Type V ◽

In Vitro Interaction

Type I collagen is the predominant collagen in the cornea with type V collagen being a quantitatively minor component. However, the content of type V collagen (10-20%) in the cornea is high when compared to other tissues containing predominantly type I collagen. The corneal stroma has a homogeneous distribution of these two collagens, however, immunochemical localization of type V collagen requires the disruption of type I collagen structure. This indicates that these collagens may be arranged as heterpolymeric fibrils. This arrangement may be responsible for the control of fibril diameter necessary for corneal transparency. The purpose of this work is to study the in vitro assembly of collagen type V and to determine whether the interactions of these collagens influence fibril morphology.

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