by Giovanie Adams
Creation Ministries International
Eukaryotic cells have systems for maintaining their shape and all their movement, and for the transport of molecules within them. Intra-cellular networks of fibers assemble from actin proteins, and are an important part of these systems. This network of actin filaments maintains cell shape by forming a support structure—an important component for cell motility—and provides the paths for the transport of molecules within the cell. The intra-cellular traffic of molecules along these paths is also necessary for cell fission (the division of one parent cell into two daughter cells). Actin filaments are also a major component of the muscle fibers of animals and are essential for the contractile apparatus of muscles.
Actin filaments are made up of two long, twisted chains consisting chiefly of tens to thousands of monomeric or globular actin proteins. The assembly and disassembly of actin filaments is controlled at each step by sets of actin-binding proteins.1 The initial assembly of a short actin filament is a rate-limiting step in filament assembly, and a subset of actin-binding proteins has been designed to overcome the relative instability of these short filaments. This process of assembling short filaments of two or three subunits from monomeric actin is called actin nucleation.
This complicated mechanism, of actin nucleation and preparation of the nucleated product for elongation by spire, suggests the work of an intelligent designer who engineered it in an incredibly intricate manner.
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