Figure 4-12. The amino acid sequences corresponding to the various mouse myelin basic proteins (MBPs) are encoded in a gene containing at least seven exons (separated by introns, DNA regions whose base sequence does not code directly for proteins).

Figure 4-12

The amino acid sequences corresponding to the various mouse myelin basic proteins (MBPs) are encoded in a gene containing at least seven exons (separated by introns, DNA regions whose base sequence does not code directly for proteins). The precursor RNA transcribed from this gene can be spliced to give a message containing all seven exons; this message codes for the 21.5-kDa MBP. Alternative splicings result in messenger RNA species with deletions of exons 2 and/or 6, which code for the other MBPs. The exons forming the various mouse messenger species are indicated above, left. The corresponding gene in humans also contains seven exons, which have minor base changes relative to the corresponding mouse sequences. Messenger RNA species derived from the human genome are indicated above, right. Messengers for the 21.5kDa and 18.5-kDa MBPs are formed in a manner analogous to that of the corresponding mouse proteins. Note, however, that the 17-kDa human protein contains a slightly different exon complement from the 17-kDa mouse MBP. (Adapted from Kamholz et al. [21].)

From: Characteristic Composition of Myelin

Cover of Basic Neurochemistry
Basic Neurochemistry: Molecular, Cellular and Medical Aspects. 6th edition.
Siegel GJ, Agranoff BW, Albers RW, et al., editors.
Philadelphia: Lippincott-Raven; 1999.
Copyright © 1999, American Society for Neurochemistry.

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