RASGRP4 Q8TDF6

RAS鸟苷酸释放蛋白4

功能描述

作为一种阳离子和二酰甘油（DAG）调节的核苷酸交换因子，通过将结合的GDP交换为GTP来激活Ras (PubMed:11880369, PubMed:11956218, PubMed:12493770, PubMed:18024961)。在中性粒细胞中，通过促进Ras介导的PIK3CG/PI3Kgamma激活以促进中性粒细胞功能反应，参与磷脂酶C激活的N-甲酰肽激活GPCR（G蛋白偶联受体）信号通路 (By similarity)。在CD117(+)树突状细胞和肥大细胞中，参与脂多糖（LPS）激活的信号通路，该通路刺激自然杀伤（NK）细胞产生干扰素-γ和其他促炎细胞因子 (By similarity)。可能在肥大细胞分化中起作用 (PubMed:11880369, PubMed:11956218, PubMed:12493770, PubMed:18024961)。似乎不是B细胞、DC细胞、T细胞或NK细胞发育所必需的 (By similarity)。 {ECO:0000250|UniProtKB:Q8BTM9, ECO:0000269|PubMed:11880369, ECO:0000269|PubMed:11956218, ECO:0000269|PubMed:12493770, ECO:0000269|PubMed:18024961}。

组织特异性

Expressed by mast cells and their progenitors (at protein level). Specifically expressed in mononuclear leukocytes. Highly expressed in myeloid cells compared to lymphoid cells. Also detected in heart, skeletal muscle, spleen, liver, placenta and lung. Not detected in brain. Isoform 1 is the major isoform in normal individuals. Isoform 2 is more significantly expressed in a patient with asthma. Isoform 3 is more significantly expressed in a patient with asthma and a mastocytosis patient.

亚细胞定位

Cytoplasm