The gene is composed of 19 exons spanning 124.5kb.

Encodes 11 confirmed splice variants in humans (Line et al., 2002; Lauffart et al., 2006). TACC1A 7735nt, TACC1A* 7521nt, TACC1B 6204nt, TACC1C 6194nt, TACC1D 6193nt,TACC1E 7345nt, TACC1F 7770nt, TACC1G 7904nt (utilizes internal splice site in exon 5), TACC1H 7319nt, TACC1I 7424nt, TACC1S 6528nt. Fully sequenced singleton cDNAs e.g. AK304507 and AK303596 suggest additional variants possible. AK304507 utilizes internal splice site in exon 5. Inclusion of alternate 5 noncoding exons indicated from expressed sequence tags identified in a global search for alternative promoters e.g. DA066351, DA950013 (Kimura et al., 2006).
Note:

AK304507 and AK303596 sequences may be suspect (see UCSC Genome Bioinformatics Site (http://genome.ucsc.edu) for more details.

Transcript/isoform nomenclature as per Line et al, 2002 and Lauffart et al., 2006. TACC1F transcript includes exon 1, 2 and 3 (correction to Fig 6 of Lauffart et al., 2006).

Partially processed pseudogene:

91% identity corresponding to base 596 to 2157 of AF049910.

• Location: 10p11.21.
  
• Location base pair: Starts at 37851943 and ends at 37873633 from pter (according to hg18-March_2006).

87% identity corresponding to base 7381 to 7742 of AF049910.

• Location: 8p21.
  
• Location base pair: Starts at 84786555 and ends at 84786906 from pter (according to hg18-March_2006).

11 confirmed splice variants generate 9 different protein isoforms. Two additional isoforms suggested by AK304507 and AK303596.
Inclusion of alternative promoters and 5 non coding exons produce one of these known protein isofroms e.g. transcripts defined by DA950013, or BQ888599 would produce TACC1E/H, transcripts defined by DA066351 would produce TACC1A/A* and transcripts defined by DC325260 would produce TACC1B.

TACC1A/TACC1A*, 805 amino acids, 87.8kDa, TACC1B 243 amino acids 19.4kDa, TACC1C 367 amino acids 40.9kDa, TACC1D 379 amino acids 42.3kDa, TACC1E/H 610 amino acids 67.1kDa, TACC1F 817 amino acids 89kDa, TACC1G 731 amino acids 79.9kDa, TACC1I 777 amino acids 84kDa, TACC1S 395 amino acids 44kDa, BAG65314 792 amino acids 86.2kDa, BAG64611 476 amino acids 51.5kDa.

Wide expression in fetus and adult. Detailed analysis reported during mouse development by Lauffart et al., 2006.

TACC1 is located in the nucleus and/or cytosol, depending on isoform and cell type (Lauffart et al., 2006). Exon 3 contains a predicted nuclear localisation signal. Most immunohistochemical analyses in sectioned tissues have used antibodies that recognize an epitope located in Exon 3. Thus, studies at the protein level have concentrated on exon 3 containing isoforms A, A*, E, F, G, H and I, but fail to differentiate between them. TACC1A weakly interacts with the centrosome during mitosis (Gergely et al., 2000). Overexpression can result in accumulation in cytoplasm in some cells resulting in oligmerisation in punctate structures (Gergely et al., 2000).

TACC1 has been proposed to function in microtubule dynamics in interphase, mitosis and cytokinesis based upon interactions with Aurora A kinase and Aurora B kinase and CKAP5 (ch-TOG/XMAP215) by interactions with the TACC domain (see Pessat and Vernos 2008 for Review). TACC1A may function in RNA splicing, decapping and/or degradation through interactions with SmG (SNRPG) and LSm-7 (LSM7) via amino acids 1-53 (Conte et al., 2002). Increased expression of TACC1A in mammary gland activates ras-MAPK and PI-3K pathways (Cully et al., 2005). The former may be due in part on TACC1A-mediated retention of pERK in the cytoplasm (Lauffart et al., 2007b). Nuclear localized TACC1 is phosphorylated on S50,S52,S54,S55,S57, cytoplasmic TACC1 is phosphorylated on S275, while Y533 is phosphorylated in Jurkat cells (Rush et al., 2005, Olsen et al., 2006). Amino acids 152-258 binds to TDRD7, but function of this interaction is unknown (Conte et al., 2003). TACC1A is a possible indirect activator of CREB via FHL family of proteins (Lauffart et al., 2007b). Uncharacterized roles in transcriptional regulation have been proposed based on TACC1 binding to GAS41 (YEATS4) via amino acid 206-427, hGCN5L2 (KAT2A), FHL coactivator/corepressor proteins and retinoid X-receptor beta via the TACC domain (Gangisetty, 2004; Lauffart et al., 2002; 2007b; 2008; Vettaikkorumakankauv et al., 2008). TACC1A can interact with BARD1 in vitro, and is phosphorylated on serine residue 44 in response to DNA damage (Matsuoka et al., 2007).
Amino acid residues involved in binding or subject to phosphorylation are quoted for TACC1A, but residues, if present in other isoforms, may also be subject to the same interactions or modifications.

Founding member of the TACC family, based on the presence of the conserved approximately 200 amino acid carboxy terminal coiled coil domain (TACC domain) (Still et al., 1999; Still et al., 2004).

To date, no mutation of TACC1 gene have been described.

Potential deletion as a result of translocation event associated with 8p11 myeloproliferative disorder (Etienne et al., 2007).