Protein Terms Links

In addition to its influence on protein—protein interactions, phosphorylation also affects protein structure and activity. One case involves a protein termed dematin headpiece (DHP), an actin-binding protein found in a variety of tissues including heart, brain, skeletal muscle, kidney, and lung." DHP is known to interact with Ras-guanine nucleotide exchange factor (Ras-GRF2) and this interaction can modulate MARK pathways, which can link the cytoskeleton and signaling pathways." ... 

In photoreceptor cells, the rods and cones of the human retina, the retinal is linked to a specific protein termed opsin. The resulting pigment is known as rhodopsin. When a photon of light of the proper wavelength hits a molecule of rhodopsin, two chemical events take place. First, the ll-c -retinal is converted to the all-trans form and, secondly, the all-trani-retinal is released from the rhodopsin ... 

The axoneme is held together by three sets of protein cross-links (see Figure 20-25a). The central pair of singlet microtubules is connected by periodic bridges, like rungs on a ladder, and is surrounded by a fibrous structure termed the inner sheath. A second set of linkers, composed of the protein nexin, joins adjacent outer doublet microtubules. Radial spokes, which radiate from the central singlets to each A tubule of the outer doublets, are proposed to regulate dynein. 

Resistin (FIZZ3), a member of a family of cysteine-rich secreted proteins termed FIZZ or RELM. Resistin is known as adipocyte-specific secretory factor. It is produced in adipose tissue. The name was coined because resistin was reported in 2001 to antagonize insulin action in cells both in vivo and in vitro, and circulating levels were increased in obese and diabetic mice. Human resistin circulates in blood as a dimer consisting of two linear 92-peptide chains linked by a disulfide bridge at Cys. Actions of resistin in humans are not well established [C. M. Stephan et al.. Nature 2001, 409, 307 U. Smith, Obes. Res. 2002, 10, 61 B. Aruna et al.. Biochemistry 2003, 42, 10554 U. Meier, A. M. Gressner, Clin. Chem. 2004, 50,1511]. 

Mesenchymal cells are spherical when in suspension and form stable protrusions only upon attachment to a surface [15]. The cells can adhere tightly to the substratum in tissue culture utilizing structures termed focal adhesions [26]. Upon extension of a lamellipod, close contacts to the substratum form, which then convert into localized adhesive clusters that can be detected using interference reflection microscopy [107, 166], These focal contacts have clusters of transmembrane proteins termed integrins that bind to extracellular matrix molecules and link intracellularly to the actin cytoskeleton to form stress fibers [251]. Adhesion to the substratum is necessary for stabilization of the lamellipod if a lamellipod extends over a nonadhesive surface, it then retracts [14],... 

Section 23.25 Carbohydrates linked to proteins, termed glycoproteins, are one example of... 

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