WD-40 repeat protein SG2NA has multiple splice variants with tissue restricted and growth responsive properties.
SG2NA is a member of the striatin family of WD-40 repeat proteins with potential scaffolding functions. It was originally identified as a tumor antigen with increased expression during S to G2 phase of cell cycle. We report here that mouse SG2NA has at least five novel splice variants of which two are devoid of the carboxyl terminal WD-40 repeats. The variants of SG2NA are generated by alternative splicing at the exon 7-9 regions and differ in their expression profiles in various tissues tested. While the 83, 78, 38 and 35 kDa variants are present in both brain and heart, the 87 kDa form is brain specific. Also, the expression of 35 kDa variant is more in neonatal than in adult tissues. Western analysis suggests that the SG2NA isoforms differentially respond to growth stimuli. Upon serum stimulation, while the 35 kDa variant is increased, the 78 kDa form is diminished. Splicing variation of SG2NA is conserved in metazoan evolution. In embryonic chicken there are at least four variants of which one is present in brain but absent in heart. Taken together, splicing variation of SG2NA might have some critical roles in differentiation and maturation in metazoan cells.
Sanghamitra
Mishra
M
School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
Talukder
Indrani
I
Singarapu
Nandini
N
Sindhu
K V
KV
Kateriya
Suneel
S
Goswami
Shyamal K
SK
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001324:Autoantigens / Q000235:genetics*; D001483:Base Sequence; D001921:Brain / Q000378:metabolism; D002148:Calmodulin-Binding Proteins / Q000235:genetics*; D002454:Cell Differentiation; D002460:Cell Line; D049109:Cell Proliferation; D002645:Chickens; D006801:Humans; D051379:Mice; D008840:Microfilament Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism; D009928:Organ Specificity; D020033:Protein Isoforms / Q000378:metabolism; D012326:RNA Splicing
D001324:Autoantigens; D002148:Calmodulin-Binding Proteins; D008840:Microfilament Proteins; D020033:Protein Isoforms; C405682:STRN3 protein, human; C485775:Strn3 protein, mouse; C118067:WDR1 protein, human