Splicing variants

AMP-activated Protein Kinase. Table 1 Information about subunit isoforms of AMP-activated protein kinase. Data refer to the full-length forms of the human isoforms. The y2 and y3 isoforms also exist as splice variants that are N-terminal truncations, with lower molecular mass and number of amino acids (38 kDa and 328 amino acids for the short form of y2, 52 kDa and 464 amino acids for the short form of y3). Other splice variants may also exist... 

Opioids act on heptahelical G-protein-coupled receptors. Three types of opioid receptors (p, 8, k) have been cloned. Additional subtypes (e.g., pl3 p2, 81 82), possibly resulting from gene polymorphisms, splice variants or alternative processing have been proposed. Opioid receptors are localized and can be activated... 

Cholinesterase. Figure 1 Shown are the seven subgroups of ChEs Molecular forms Top, in green monomeric, dimeric and tetrameric AChE-S forms (G1, G2, G4 and PRiMA). Middle, in green ColQtailed AChE-S forms (A4, A8 and A12). Parallel forms exist for BChE. Down other AChE splicing variants (AChE-R, AChE-E, N-AChE). 

Two isotypes of SUR have been cloned, SUR1 and SUR2. In addition, two splicing variants of SUR2, distinguished by 42 C-terminal amino acids, have been... 

FGF (22 members) FGFs require heparan sulfate to activate their receptors FGFR Four members expressed as a number of splice variants Proliferation of many cell types. Embryo patterning and organogenesis, bone development, angiogenesis... 

SCF Due to splice variants there are soluble and membrane forms of SCF KIT/SCFR Hematopoiesis, gametogenesis, and me-lanogenesis... 

Several splice variants of MOP (formerly MOR-1) have been cloned (MOP-1A to MOR-1X). The B, C, andD variants differ in their amino acid sequence at the C-terminal end [4]. These receptor valiants differ in their distribution in the central nervous system and in the rate of internalization and desensitization upon... 

PDE Family Genes Probable splice variants Regulatory domains/role Phosphorylation Substrate (s) Commonly used inhibitors... 

Prostanoids. Figure 2 EP3 receptor sequence of three mouse EP3 receptor splice variants differing only in their intracellular carboxyl termini. The predicted amino acid sequences of each splice variant are represented by the one letter amino acid code. The common region is comprised of two exons, which are spliced to three possible C-terminal tails. The carboxyl variable tails are designated alpha, beta, and gamma,each encoded by distinct exons. 

A splice variant can arise when a gene contains at least two introns leading to the possibility that the DNA between them (an exon) may not be included in the final mRNA and protein product. Thus, the final protein product may exist in two forms one containing the amino-acid sequence encoded by the exon that is located between the introns in the original DNA, and another form in which the amino-acid sequence encoded by that exon has been spliced out . These two products are refened to as splice variants. 

TK NKxr, NK2r, and NK3r are encoded by three genes termed as TACR1, TACR2, and TACR3, respectively. Splice variants of these TK receptors have also been identified (Table 3). 

Two NKxr splice variants have been identified (Table 3). A NKxr splice variant having a very short C-terminal intracellular tail (7 instead of 96 amino acids), which has been expressed and characterized in recombinant systems (Fig. 1), was found to be expressed at higher level than the long isoform in breast cancer cells. As compared to the long receptor, the short NKxr isoform is less subjected to desensitization and internalization... 

Beyond the classic NK3r, an mRNA splice variant has been also recently identified but no data on its expression and function are available yet, although the extensive deletion of critical regions renders unlikely its functionality (Table 3) [5]. NK3r has been much less... 

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