Ab l1

Figure 1 A Schematic of Neuropilin Signaling Complexes. (A) In this model, VEGF165 bridges NRP1 (via axon 7) and the tyrosine kinase receptor VEGFR-2 (via exon 4). There are no direct NRP1/VEGFR-2 interactions. VEGF165 and NRP1 also bind HSPG. The NRP1 binding site for VEGF165 and HSPG is the b1b2 domain. It is suggested that the formation of a complex between VEGF165 and the three receptors enhances VEGF165 binding to VEGFR-2, which initiates the cellular signaling cascade, and as a consequence enhances VEGF165 activity such as chemotaxis of endothelial cells and angiogenesis. (B) Sema3Abinds to the a1a2 and b1b2 domains of NRP1. NRP1 binds to the transmembrane proteins plexin A and L1. The complex formation enhances the binding of Sema3A to NRP1, and subsequently plexin A induces the signaling events that lead to repulsion of axons and of neuronal cells.

Figure 1 A Schematic of Neuropilin Signaling Complexes. (A) In this model, VEGF165 bridges NRP1 (via axon 7) and the tyrosine kinase receptor VEGFR-2 (via exon 4). There are no direct NRP1/VEGFR-2 interactions. VEGF165 and NRP1 also bind HSPG. The NRP1 binding site for VEGF165 and HSPG is the b1b2 domain. It is suggested that the formation of a complex between VEGF165 and the three receptors enhances VEGF165 binding to VEGFR-2, which initiates the cellular signaling cascade, and as a consequence enhances VEGF165 activity such as chemotaxis of endothelial cells and angiogenesis. (B) Sema3Abinds to the a1a2 and b1b2 domains of NRP1. NRP1 binds to the transmembrane proteins plexin A and L1. The complex formation enhances the binding of Sema3A to NRP1, and subsequently plexin A induces the signaling events that lead to repulsion of axons and of neuronal cells.

mutated NRP1 that cannot bind Sema3A exhibited normal vasculature. On the other hand, in a different mouse background, Sema3A knockouts showed vascular defects in the head and had abnormal trunk blood vessels. These discrepancies as to whether Sema3A does or does not regulate the vasculature could be a result of the use of different developmental models and methodologies and will hopefully be reconciled in the future.

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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