Rat brain이 성장하는 동안 Ins(1,4,5)$P_3$ 3-Kinase의 활성도가 14배 증가하였다. 면역학적으로 서로 다른 $IP_3$ 3-Kinase가 적어도 3가지 있었다(53 kDa, 51 kDa 및 40 kDa). $IP_3$ 3-Kinase에 특이성이 있는 모노클로날 항체와 cDNA를 probe로 사용하여 단백질과 mRNA의 양을 정량하였다. 한 가지 형태의 mRNA가 확인되었고, Parallel하며, 어린단계에서는 $IP_3$ 3-Kinase와 mRNA가 전혀 나타나지 않았으나 1주일 후에는 갑자기 증가하였다. 실험결과 흰쥐의 뇌가 성장하는 동안 $IP_3$ 3-Kinase는 transcriptional 수준으로 조절 받는 것이 확인되었다.
The enzymic activities of Ins(1,4,5)$P_3$ 3-Kinase increased by 14-fold during the development of rat brain from fetus to adult. Rat brain contains at least three immunologically distinct $IP_3$ 3-Kinases(53 kDa, 51kDa and 40kDa). Using molecular probes (monoclonal Ab and cDNA) specific to the $IP_3$ 3-Kinase, we quantitated the concentration of protein and mRNA of these enzymes during development, these enzymes were qualitatively paralleled by the changes in concentrations of mRNAs. These experiments with $IP_3$ 3-Kinase indicate that there is only one form of mRNA. At early stage, both $IP_3$ 3-Kinase protein and mRNA were barely detectible. Their intensities increased suddenly at a week after birth. These results suggest that the concentration of the $IP_3$ 3-Kinase are regulated at transcriptional level during brain development.
