You are studying the production of an extracellular matrix by cultures of fibroblasts isolated from a melanoma. Histological studies demonstrate an absence of merosin. Based upon this finding, which of the following ECM components is most likely not being synthesized or processed appropriately in your cell culture system?

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Quizplus · Accepted Answer

Merosin is a specific isoform of laminin, so an absence of merosin indicates a problem with the synthesis or processing of laminin in the extracellular matrix. Laminins are heterotrimeric proteins that have been found to form at least 15 different types of heterotrimers. Laminin heterotrimers are quite large, ranging from under 500,000 to nearly a 1,000,000 Da in mass. Laminins contain common structural features that include a tandem distribution of globular, rod-like, and coiled-coil domains. The coiled-coil domains are responsible for joining the 3 chains into the characteristic heterotrimeric structure called merosin

You Are Studying the Production of an Extracellular Matrix by Cultures