Basement membranes are cell-associated heteropolymers, assembled from laminins, type IV collagen, nidogen and proteoglycans that act both as substratum and solid-phase agonist. They are involved in the development and maintenance of animal tissues, with defects causing diseases that affect kidney, muscle, nerve and skin. The mouse laminin gamma1-null phenotype is one of peri-implantation lethality, and cultured embryoid bodies (EBs) derived from null embryonic stem (ES) cells fail to form basement membrane or to gastrulate. This EB-differentiation system provides a model with which to study the relationships that exist between laminin structure and its biological functions during gastrulation and, more generally, for the roles played by basement membranes in the formation and regulation of organized and differentiated tissues. The goal of the next funding period is to elucidate molecular mechanisms that operate through laminin in basement membrane assembly and cellular differentiation, focusing on the laminin loci that engage select cell surfaces, mediate polymerization to create a cell substratum, affect incorporation of other components into basement membrane, and induce inner cell mass (ICM) differentiation. Building upon an ability to engineer heterotrimeric laminins with altered function through specific mutations, modified recombinant laminins will be evaluated for their effects in EBs that are defective in their ability to spontaneously form basement membrane, epiblast, or mesoderm due to genetic defects in laminin, beta1-integrin, dystroglycan, heparan sulfate and/or growth factor receptors.
Aim I will address how the modules of laminin G-domain provide critical anchorage at the endoderm/ICM interface. The roles of candidate sequences and their cell surface targets will be analyzed.
Aim II will address how G-domain interactions with beta1-integrin, dystroglycan and other receptors regulate basement membrane assembly, initiate signaling and affect EB differentiation.
Aim III will address the globular and rod domains of the short arms in ECM architecture, analyzing their roles in polymerization, scaffold stability, incorporation of type IV collagen into matrix, cell adhesion, and polymer contributions to signaling. ? ?
|Pozzi, Ambra; Yurchenco, Peter D; Iozzo, Renato V (2017) The nature and biology of basement membranes. Matrix Biol 57-58:1-11|
|van Wijk, Xander M; Döhrmann, Simon; Hallström, Björn M et al. (2017) Whole-Genome Sequencing of Invasion-Resistant Cells Identifies Laminin ?2 as a Host Factor for Bacterial Invasion. MBio 8:|
|Colombelli, Cristina; Palmisano, Marilena; Eshed-Eisenbach, Yael et al. (2015) Perlecan is recruited by dystroglycan to nodes of Ranvier and binds the clustering molecule gliomedin. J Cell Biol 208:313-29|
|Hohenester, Erhard; Yurchenco, Peter D (2013) Laminins in basement membrane assembly. Cell Adh Migr 7:56-63|
|McKee, Karen K; Yang, Dong-Hua; Patel, Rajesh et al. (2012) Schwann cell myelination requires integration of laminin activities. J Cell Sci 125:4609-19|
|Yurchenco, Peter D (2011) Basement membranes: cell scaffoldings and signaling platforms. Cold Spring Harb Perspect Biol 3:|
|Yang, Dong-Hua; McKee, Karen K; Chen, Zu-Lin et al. (2011) Renal collecting system growth and function depend upon embryonic ?1 laminin expression. Development 138:4535-44|
|He, Xiaowen; Liu, Jie; Qi, Yanmei et al. (2010) Rac1 is essential for basement membrane-dependent epiblast survival. Mol Cell Biol 30:3569-81|
|McKee, Karen K; Capizzi, Stephanie; Yurchenco, Peter D (2009) Scaffold-forming and Adhesive Contributions of Synthetic Laminin-binding Proteins to Basement Membrane Assembly. J Biol Chem 284:8984-94|
|Yurchenco, Peter D; Patton, Bruce L (2009) Developmental and pathogenic mechanisms of basement membrane assembly. Curr Pharm Des 15:1277-94|
Showing the most recent 10 out of 35 publications