Fibrillar repetitive structure surrounding the ventral disc edge in Giardia species (trophozoite stage). The composition of the lateral crest is not fully known yet.

A region of the ventral disc of Giardia species (trophozoite stage) where two portions of the same array of microtubules overlap (the microtubule array makes a complete circle and overlaps on itself).

A part of the ventral disc of Giardia species (trophozoite stage) consisting of a spiral array of microtubules linked to the ventral membrane. These microtubules form the base of the ventral disc dorsal microribbons that extend nearly perpendicular from the membrane.

Trilaminar structure extending perpendicularly into the cytoplasm along the length of ventral disc microtubules in Giardia species (trophozoite stage). Constituents of dorsal microribbons (also called dorsal ribbons or microribbons) include alpha-coiled-helix proteins approximately 29 to 38 kDa in size. These proteins line the edges of the microribbons but are not found in microtubules. Tubulins are not found in microribbons.

Structure horizontally linking adjacent microribbons of the ventral disc in Giardia species (trophozoite stage). The composition of crossbridges is not fully known yet.

A partial left-handed spiral array of microtubules that lies generally dorsal to the main ventral disc microtubule array in Giardia species (trophozoite stage).

Specialized organelle found in Giardia species (trophozoite stage) and characterized by a spiral array of microtubules and microtubule-associated structures including dorsal microribbons and crossbridges. The edge of the ventral disc narrows into a lateral crest. The ventral disk mediates mechanical attachment of the trophozoite to the host's intestinal wall, and contains the contractile proteins actinin, alpha-actinin, myosin, and tropomyosin working towards contraction of the disk involved in adherence.

A small amount of cytoplasm surrounded by a cell membrane that is generally retained in spermatozoa after spermiogenesis, when the majority of the cytoplasm is phagocytosed by Sertoli cells to produce what are called residual bodies. Initially, the droplet is located at the neck just behind the head of an elongated spermatid. During epididymal transit, the cytoplasmic droplet migrates caudally to the annulus at the end of the midpiece; the exact position and time varies by species. The cytoplasmic droplet consists of lipids, lipoproteins, RNAs, a variety of hydrolytic enzymes, receptors, ion channels, and Golgi-derived vesicles. The droplet may be involved in regulatory volume loss (RVD) at ejaculation, and in most species, though not in humans, the cytoplasmic droplet is lost at ejaculation. Note that the cytoplasmic droplet is distinct from 'excessive residual cytoplasm' that sometimes remains in epididymal spermatozoa, particularly when spermiogenesis has been disrupted.

Catalysis of the reaction: 2-polyprenyl-6-hydroxyphenol + S-adenosyl-L-methionine = 2-polyprenyl-6-methoxyphenol + S-adenosyl-L-homocysteine + H+.

Binding to a histone H4 in which the lysine residue at position 20 has been modified by trimethylation.

Binding to a histone in which a residue has been modified by methylation.

Catalysis of the reaction: 2-polyprenyl-3-methyl-5-hydroxy-6-methoxy-1,4-benzoquinol + S-adenosyl-L-methionine = ubiquinol-n + S-adenosyl-L-homocysteine + H+.

The posttranscriptional addition of one or more acetyl groups to specific residues in an RNA molecule.

OBSOLETE. Binding to a protein serine/threonine kinase.

The modification of rRNA structure by addition of an acetyl group to rRNA. An acetyl group is CH3CO-, derived from acetic [ethanoic] acid.

The covalent alteration of one or more nucleotides within an rRNA molecule to produce an rRNA molecule with a sequence that differs from that coded genetically.

Catalysis of the reaction: acetyl-CoA + cytidine = CoA + N4-acetylcytidine. The cytidine is within the polynucleotide chain of an rRNA.

Any process that reduces or removes the toxicity of copper ions in a cell. These include transport of copper cations away from sensitive areas and to compartments or complexes whose purpose is sequestration.

OBSOLETE. Any process that stops, prevents, or reduces the frequency, rate or extent of transcription from an RNA polymerase II promoter as a result of DNA damage.