Alternative splicing and gene polymorphism of the human TAP3/SEC14L4 gene

Abstract

Three closely related human SEC14p-like proteins (hTAP1, hTAP2, hTAP3, or SEC14L2, SEC14L3, SEC14L4, respectively) have been described that are related to the Saccharomyces cerevisiae SEC14 protein. These proteins may participate in intracellular lipid transport and influence regulatory lipid-dependent events. Here we report the isolation of an alternatively spliced hTAP3 cDNA and a polymorphism within the coding region of the hTAP3/SEC14L4 gene.

Elevation of transcription factor Islet-1 levels in vivo increases β-cell function but not β-cell mass

“…3B). From our real-time PCR, we detected an increase in the expression of Afamin, 23 Caps2, 21,22 Slc2a10, 26,27 Sec14l4, 24,25 and P2rx7 [18][19][20] as well as Neurogenin3 28 in the Pdx1 PB -Isl-1-Myc islets (Fig. 3B).…”

“…These genes are implicated to function in protein trafficking and metabolism, and may play important roles in β-cell biology. In this analysis, we were able to detect an increase in Slc2a10 (Glut10), a gene that has been implicated in glucose metabolism and type 2 diabetes, 26,27 increased levels of SEC14L4, a factor that has been implicated to be involved in secretion in organs like salivary gland, prostate and pancreas, 24,25 and a 35-fold increase in Afamin levels, a transporter for α-tocopherol in the CNS. 23 Additionally, P2rx7, a purinergic receptor with implicated function for regulating both endocrine and exocrine pancreas function and Caps2, transgenic mouse line was characterized in our study, which we acknowledged it as a caveat, we are confident that the effects we observe in the Pdx1 PB -Isl-1-Myc mice are due to the elevation of Isl-1 expression as Arx and MafA, two genes that are downregulated in Isl-1 deficient pancreata, 10,11 were increased the islets of the Pdx1 PB -Isl-1-Myc transgenic mice.…”

“…Interestingly, both Caps2 and P2rx7 have implicated functions in regulating secretion by affecting Ca 2+ signaling through binding to Ca 2+ (Caps2) and mediating the effect of ATP (P2rx7), respectively. [18][19][20][21][22] In contrary, while Afamin and Sec14l4 have no known functions in mediating insulin secretion, they have been implicated in transport of α-tocopherol, a form of vitamin E. [23][24][25] Based on their involvement in transport, these proteins may play crucial roles in regulating exocytosis and vesicular transport in islet β-cells. Additionally, with the implicated functions of Slc2a10 (Glut10), a facilitated glucose transporter and Neurogenin3 in maintaining glucose homeostasis, [26][27][28][29][30][31] our study suggest that increased levels of these genes potentially lead to the enhanced β-cell function seen in the Pdx1 PB -Isl-1-Myc transgenic mice.…”

Sec14l3 Is Specifically Expressed in Mouse Airway Ciliated Cells

“…Three closely related human SEC14p-like proteins (hTAP1, hTAP2, and hTAP3, or SEC14L2, SEC14L3, and SEC14L4, respectively) have been described. These proteins may participate in intracellular lipid transport and influence regulatory lipid-dependent events [40]. The hTAP2 (SEC14L3) mRNA and protein have been reported to be expressed in lung [41,42].…”

Complexity of vitamin E metabolism

“…In humans, three highly homologous TAP proteins, namely TAP1/SEC14-like 2 protein (SEC14L2; synonymously, supernatant protein factor, SPF), TAP2/SEC14L3 and TAP3/SEC14L4, have been described [121,122] , but the contribution of TAP2 and TAP3 to the transport and metabolism of vitamin E has not yet been investigated. TAP 1 and α-TTP belong to a family of ligand-binding proteins that have a cis-retinal binding motif sequence, the so-called CRAL-TRIO domain.…”