Dictionary > Nexin

Nexin

Definition
noun
The protein in the interdoublet link that connects the adjacent microtubule doublets of the ciliary axoneme
Supplement
Within the cilia and the flagella of eukaryotes is a microtubule-based cytoskeleton referred to as the axoneme. A cross-section of the axoneme reveals nine sets of microtubule doublets forming a ring inside the cilium or flagellum. (Motile cilia and flagella have an additional two singlet microtubules at the center apart from the ring of microtubule doublets, thus forming a ” 9+2″ configuration).
Connecting the microtubule doublet to the adjacent doublet is the interdoublet link. The role of interdoublet link is not yet fully understood but it may be providing support to the axoneme during an active doublets sliding.1
Nexin is the interdoublet link protein responsible for the maintenance of the nine-fold configuration in cilia and flagella. It was first isolated by R.E. Stephens. In his report in 1970, he named this protein nexin, from the Latin nexus, which means “a tie binding together members of a group”. 2 He was able to isolate nexin from Strongylocentrotus drocbachiensis, Asterias sp., and Arbacia punctulata” sperm flagella through SDS-PAGE. The protein, according to Stephens, represents about 2% of the total axonemal protein, and less than 1% of the total flagellar protein. Its molecular weight is 165,000 +/- 10%.2
See also:

Related term(s):

  • Protease nexin
  • Reference(s):

    1 Bourne, G. (1987). Cytology and cell physiology (4th ed.). San Diego: Academic Press.

    2 Stephens, R.E. (1970). Isolation of nexin—the linkage protein responsible for maintenance of the nine-fold configuration of flagellar axonemes. Biol Bull 139: 438.


    You will also like...

    mRNA
    Protein Synthesis

    Part of the genetic information is devoted to the synthesis of proteins. mRNA, a type of RNA, is produced as a transcri..

    Buttress roots
    Roots

    This study guide tackles plant roots in greater detail. It delves into the development of plant roots, the root structur..

    Neural Control Mechanisms
    Neural Control Mechanisms

    Neurons generate electric signals that they pass along to the other neurons or target tissues. In this tutorial, you wil..

    Control of body movement
    Control of Body Movement

    Some of the body movements can be controlled at will, others cannot. The body has a motor program, which is the pattern ..

    Chromosome Mutations
    Chromosome Mutations

    Mutations can also influence the phenotype of an organism. This tutorial looks at the effects of chromosomal mutations, ..

    DNA molecule
    Genetic Control – On and Off Genes

    Genes are the blueprint of our bodies, a blueprint that creates a variety of proteins essential to any organism's surviv..