Publications by authors named "Ewa Koper"

Integrin receptor activation initiates the formation of integrin adhesion complexes (IACs) at the cell membrane that transduce adhesion-dependent signals to control a multitude of cellular functions. Proteomic analyses of isolated IACs have revealed an unanticipated molecular complexity; however, a global view of the consensus composition and dynamics of IACs is lacking. Here, we have integrated several IAC proteomes and generated a 2,412-protein integrin adhesome.

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Integrin activation, which is regulated by allosteric changes in receptor conformation, enables cellular responses to the chemical, mechanical and topological features of the extracellular microenvironment. A global view of how activation state converts the molecular composition of the region proximal to integrins into functional readouts is, however, lacking. Here, using conformation-specific monoclonal antibodies, we report the isolation of integrin activation state-dependent complexes and their characterization by mass spectrometry.

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Integrin alpha5beta1 is a key receptor for the extracellular matrix protein fibronectin. Antagonists of human integrin alpha5beta1 have therapeutic potential as anti-angiogenic agents in cancer and diseases of the eye. However, the structure of the integrin is unsolved and the atomic basis of fibronectin and antagonist binding by integrin alpha5beta1 is poorly understood.

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Extracellular matrixes (ECMs) coat and subdivide animal tissues, but it is unclear how ECM formation is restricted to tissue surfaces and specific cell interfaces. During zebrafish somite morphogenesis, segmental assembly of an ECM composed of Fibronectin (FN) depends on the FN receptor Integrin alpha5beta1. Using in vivo imaging and genetic mosaics, our studies suggest that incipient Itgalpha5 clustering along the nascent border precedes matrix formation and is independent of FN binding.

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Dendritic spines are a characteristic feature of a number of neurons in the vertebrate nervous system and have been implicated in processes that include learning and memory. In spite of this, there has been no comprehensive analysis of the presence of spines in a classical genetic system, such as Drosophila, so far. Here, we demonstrate that a subset of processes along the dendrites of visual system interneurons in the adult fly central nervous system, called LPTCs, closely resemble vertebrate spines, based on a number of criteria.

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