Transcription Elongation Factor

TCEB1 (elongin C) is a subunit of elongin, which is a common transcription elongation factor that increases the RNA polymerase II transcription elongation past template encoded arresting sites. The SIII complex is comprised of elongins A/A2, B and C. The SIII complex activates elongation by RNA polymerase II by curbing transient pausing of the polymerase at numerous sites within transcription units. Elongin A acts as the transcriptionally active component of the SIII complex, while elongins B and C are regulatory subunits. Elongin A2 is specifically expressed in the testis, and able to forming a stable complex with elongins B and C. The VHL (von Hippel-Lindau) tumor suppressor protein binds to elongins B and C, and thus inhibits transcription elongation.

Transcription elongation factor A protein-like 8 (TCEAL8) is a member of the TFS-II family and TFA subfamily. TCEAL8 is involved in transcriptional regulation and localized in nucleus. TFS-II family members contain TFA domains and act as nuclear phosphoproteins which control transcription in a promoter context-dependent mode. Numerous family members are found on the X chromosome.

Transcription Elongation Factor A (SII)-Like 7 (TCEAL7) has a role in the negative regulation of NF-kappa-B signaling at the basal level by controlling transcriptional activity of NF-kappa-B on its target gene promoters. TCEAL7 links with cyclin D1 promoter containing Myc E-box sequence and transcriptionally inhibits cyclin D1 expression. TCEAL7 regulates telomerase reverse transcriptase expression and telomerase activity in both alternative lengthening of telomeres (ALT) and telomerase-positive cell lines. TCEAL7 is highly expressed in normal and fetal brain tissues, and weakly expressed in the uterus and ovary. TCEAL7 is down-regulated in epithelial ovarian, cervical, prostate, breast, brain and lung cancer cell lines and in the brain and ovarian tumors.

TCEAL3 belongs to the transcription elongation factor A (SII)-like (TCEAL) gene family. TCEAL family members hold TFA domains and operate as nuclear phosphoproteins which control transcription in a promoter context-dependent fashion. Various family members are situated in the X chromosome.

Transcription elongation factor A protein-like 1 (TCEAL1) is a member of the transcription elongation factor A (SII)-like (TCEAL) family, which may function as nuclear phosphoproteins that modulate transcription in a promoter context-dependent manner. TCEAL1 is involved in transcriptional regulation. TCEAL1 is expressed in all tissues, especially highly expressed in the heart, ovary, prostate and skeletal muscle.

Transcription Elongation Factor A (SII)- 2 (TCEA2) is located in the nucleus, where it serves as an SII class transcription elongation factor. Elongation factors in this class are responsible for discharging RNA polymerase II ternary complexes from transcriptional arrest at template-encoded arresting sites. TCEA2 interacts with general transcription factor IIB, a basal transcription factor.

TCEA1 is a member of the TFS-II family. TCEA1 binds to Pol II and operates to cleave the emerging transcript, thus unlocking the complex and permitting transcription to continue. TCEA1 is localized to the nucleus and holds three independently-folding domains that are essential for accurate binding to Pol II. The arresting sites in are able to trap a certain segment of elongating RNA polymerases that goes through, causing in a locked ternary complex. Cleavage of the emerging transcript by S-II enables the renewal of elongation from the new 3'-terminus.

Elongin B (Elob) is a subunit of the transcription factor B (SIII) complex. SIII complex is a general transcription elongation factor that increases the RNA polymerase II transcription elongation past template-encoded arresting sites. The SIII complex comprised of a transcriptionally active subunit (A) and 2 regulatory subunits (B and C). Subunit A is transcriptionally active and its transcription activity is enhanced by binding to the dimeric complex of the SIII regulatory subunits B and C. The von Hippel-Lindau tumor suppressor protein binds to elongin B and C and inhibits transcription elongation.

TCEB2 is a subunit of the SIIII complex which is a heterotrimer consisting of a transcriptionally active subunit (A) and two regulatory subunits (B and C). TCEB2 initiates elongation by RNA polymerase II by suppressing transient pausing of the polymerase at many sites within transcription units. The von Hippel-Lindau tumor suppressor protein binds to elongins B and C, and thereby inhibits transcription elongation.